T89C51RD2 0 to 40MHz Flash Programmable 8-bit Microcontroller 1. Description ATMEL Wireless and Microcontrollers T89C51RD2 is high performance CMOS Flash version of the 80C51 CMOS single chip 8-bit microcontroller. It contains a 64 Kbytes Flash memory block for program and for data. The 64 Kbytes Flash memory can be programmed either in parallel mode or in serial mode with the ISP capability or with software. The programming voltage is internally generated from the standard VCC pin. The T89C51RD2 retains all features of the ATMEL Wireless and Microcontrollers 80C52 with 256 bytes of internal RAM, a 7-source 4-level interrupt controller and three timer/counters. In addition, the T89C51RD2 has a Programmable Counter Array, an XRAM of 1024 bytes, an EEPROM of 2048 bytes, a Hardware Watchdog Timer, a more versatile serial channel that facilitates multiprocessor communication (EUART) and a speed improvement mechanism (X2 mode). Pinout is either the standard 40/ 44 pins of the C52 or an extended version with 6 ports in a 64/68 pins package. The fully static design of the T89C51RD2 allows to reduce system power consumption by bringing the clock frequency down to any value, even DC, without loss of data. The T89C51RD2 has 2 software-selectable modes of reduced activity for further reduction in power consumption. In the idle mode the CPU is frozen while the peripherals and the interrupt system are still operating. In the power-down mode the RAM is saved and all other functions are inoperative. The added features of the T89C51RD2 makes it more powerful for applications that need pulse width modulation, high speed I/O and counting capabilities such as alarms, motor control, corded phones, smart card readers. 2. Features * 80C52 Compatible * * 8051 pin and instruction compatible * Four 8-bit I/O ports (or 6 in 64/68 pins packages) * Three 16-bit timer/counters * 256 bytes scratch pad RAM * 7 Interrupt sources with 4 priority levels ISP (In System Programming) using standard VCC power supply. * Boot FLASH contains low level FLASH programming routines and a default serial loader * High-Speed Architecture * * 40 MHz in standard mode * 20 MHz in X2 mode (6 clocks/machine cycle) 64K bytes on-chip Flash program / data Memory * * Byte and page (128 bytes) erase and write * 10k write cycles On-chip 1024 bytes expanded RAM (XRAM) * Software selectable size (0, 256, 512, 768, 1024 bytes) * 768 bytes selected at reset for T87C51RD2 compatibility Rev. F - 15 February, 2001 * Dual Data Pointer * Variable length MOVX for slow RAM/peripherals * Improved X2 mode with independant selection for CPU and each peripheral * 2 k bytes EEPROM block for data storage * 100K Write cycle * Programmable Counter Array with: * High Speed Output, * Compare / Capture, * Pulse Width Modulator, * Watchdog Timer Capabilities Asynchronous port reset * * Full duplex Enhanced UART * Low EMI (inhibit ALE) * Hardware Watchdog Timer (One-time enabled with Reset-Out) * Power control modes: * Idle Mode. * Power-down mode. 1 T89C51RD2 * Power supply: - M version: Commercial and industrial 4.5V to 5.5V : 40MHz X1 Mode, 20MHz X2 Mode 3V to 5.5V : 33MHz X1 Mode, 16 MHz X2 Mode - L version: Commercial and industrial 2.7V to 3.6V : 25MHz X1 Mode, 12MHz X2 Mode Temperature ranges: Commercial (0 to +70C) and industrial (-40 to +85C). * * Packages: PDIL40, PLCC44, VQFP44, PLCC68, VQFP64 Table 1. Memory Size PDIL40 PLCC44 Flash (bytes) EEPROM (bytes) XRAM (bytes) TOTAL RAM (bytes) I/O 64k 2k 1024 1280 32 VQFP44 1.4 T89C51RD2 PLCC68 Flash (bytes) EEPROM (bytes) XRAM (bytes) TOTAL RAM (bytes) I/O 64k 2k 1024 1280 48 VQFP64 1.4 T89C51RD2 (3) (3) (1) (1) (1) T2 T2EX PCA ECI Vss VCC TxD RxD 3. Block Diagram (1) XTAL1 EUART XTAL2 ALE/ PROG C51 CORE PSEN Flash 64Kx8 RAM 256x8 XRAM EEPROM 1Kx8 2Kx8 PCA Timer2 IB-bus CPU EA Watch Dog P5 P4 P3 P2 Port 0 Port 1 Port 2 Port 3 Port 4 Port 5 (2) (2) P1 INT1 (3) (3) T1 (3) (3) Parallel I/O Ports & Ext. Bus P0 INT Ctrl INT0 Timer 0 Timer 1 (3) RESET WR (3) T0 RD (1): Alternate function of Port 1 (2): Only available on high pin count packages (3): Alternate function of Port 3 2 Rev. F - 15 February, 2001 T89C51RD2 4. SFR Mapping The Special Function Registers (SFRs) of the T89C51RD2 fall into the following categories: * * * * * * * * * C51 core registers: ACC, B, DPH, DPL, PSW, SP, AUXR1 I/O port registers: P0, P1, P2, P3, P4, P5 Timer registers: T2CON, T2MOD, TCON, TH0, TH1, TH2, TMOD, TL0, TL1, TL2, RCAP2L, RCAP2H Serial I/O port registers: SADDR, SADEN, SBUF, SCON Power and clock control registers: PCON Hardware Watchdog Timer register: WDTRST, WDTPRG Interrupt system registers: IE, IP, IPH Flash and EEPROM registers: FCON, EECON, EETIM Others: AUXR, AUXR1, CKCON Table below shows all SFRs with their address and their reset value. Bit addressable 0/8 E8h E0h D8h D0h C8h C0h B8h B0h A8h A0h 98h 90h 88h 80h 1/9 CH 0000 0000 F8h F0h Non Bit addressable B 0000 0000 P5 1111 1111 ACC 0000 0000 CCON 00X0 0000 PSW 0000 0000 T2CON 0000 0000 P4 1111 1111 IP X000 000 P3 1111 1111 IE 0000 0000 P2 1111 1111 SCON 0000 0000 P1 1111 1111 TCON 0000 0000 P0 1111 1111 0/8 2/A 3/B 4/C 5/D 6/E 7/F CCAP0H CCAP1H CCAPL2H CCAPL3H CCAPL4H XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX FFh F7h CL 0000 0000 CCAP0L CCAP1L CCAPL2L CCAPL3L CCAPL4L XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX EFh E7h CMOD CCAPM0 00XX X000 X000 0000 FCON EECON XXXX 0000 XXXX XX00 T2MOD RCAP2L XXXX XX00 0000 0000 CCAPM1 X000 0000 EETIM 0000 0000 RCAP2H 0000 0000 CCAPM2 X000 0000 CCAPM3 X000 0000 CCAPM4 X000 0000 DFh D7h TL2 0000 0000 TH2 0000 0000 CFh P5 1111 1111 SADEN 0000 0000 C7h BFh IPH X000 0000 SADDR 0000 0000 B7h AFh AUXR1 XXXX 00X0 WDTRST WDTPRG XXXX XXXX XXXX X000 SBUF XXXX XXXX A7h 9Fh 97h TMOD 0000 0000 SP 0000 0111 TL0 0000 0000 DPL 0000 0000 TL1 0000 0000 DPH 0000 0000 TH0 0000 0000 1/9 2/A 3/B 4/C Rev. F - 15 February, 2001 TH1 0000 0000 5/D AUXR XX0X 1000 6/E CKCON X000 0000 PCON 00X1 0000 8Fh 87h 7/F 3 T89C51RD2 reserved 4 Rev. F - 15 February, 2001 T89C51RD2 6 7 8 31 30 EA ALE/PROG PSEN P2.7/AD15 P2.6/AD14 P2.5/AD13 P3.6/WR 16 25 P3.7/RD XTAL2 17 18 19 20 24 XTAL1 P0.6/AD6 RST 10 36 P0.7/AD7 P3.0/RxD 35 34 33 EA P3.1/TxD 11 12 13 P2.4/AD12 P2.3/AD11 P3.2/INT0 P3.3/INT1 14 15 32 31 PSEN P2.2/AD10 P3.4/T0 P3.5/T1 16 30 P2.6/A14 17 29 P2.5/A13 NIC* P2.1/AD9 PLCC NIC* ALE/PROG P2.7/A15 P0.3/AD3 P0.2/AD2 P0.1/AD1 P0.0/AD0 VCC VSS1/NIC* P1.0/T2 P1.1/T2EX P1.2/ECI P1.3/CEX0 P1.4/CEX1 P0.5/AD5 18 19 20 21 22 23 24 25 26 27 28 P2.0/AD8 P3.6/WR VSS 23 22 21 37 P2.3/A11 P2.4/A12 27 26 9 P2.2/A10 P3.5/T1 14 15 P3.4/T0 P1.7/CEx4 P2.1/A9 29 28 39 38 P0.4/AD4 P1.6/CEX3 7 8 NIC* P2.0/A8 PDIL P1.5/CEX2 VSS 11 12 13 P1.4/CEX1 32 10 6 5 4 3 2 1 44 43 42 41 40 P0.6/AD6 XTAL1 P3.2/INT0 P3.3/INT1 9 P0.7/AD7 P0.5/AD5 XTAL2 P3.0/RxD P3.1/TxD P0.3/AD3 P0.4/AD4 P3.7/RD P1.6/CEX3 P1.7CEX4 RST 36 35 34 33 5 P0.2/AD2 P0.3/AD3 P1.5/CEX2 P0.1/AD1 P0.2/AD2 37 P0.1/AD1 3 4 P0.0/AD0 P1.2/ECI P1.3CEX0 P1.4/CEX1 VCC P0.0/AD0 VSS1/NIC* VCC 39 38 P1.0/T2 40 2 P1.1/T2EX 1 P1.2/ECI P1.0/T2 P1.1/T2EX P1.3/CEX0 5. Pin Configuration 44 43 42 41 40 39 38 37 36 35 34 33 32 P0.4/AD4 31 P0.6/AD6 30 P0.7/AD7 29 28 27 EA PSEN 9 26 25 10 24 P2.6/A14 11 23 P2.5/A13 P1.5/CEX2 P1.6/CEX3 1 P1.7/CEX4 RST 3 4 P3.0/RxD 5 NIC* 6 7 8 P3.1/TxD P3.2/INT0 P3.3/INT1 P3.4/T0 P3.5/T1 2 VQFP44 1.4 P0.5/AD5 NIC* ALE/PROG P2.7/A15 P2.3/A11 P2.4/A12 P2.2/A10 P2.1/A9 NIC* P2.0/A8 VSS XTAL1 XTAL2 P3.7/RD P3.6/WR 12 13 14 15 16 17 18 19 20 21 22 *NIC: No Internal Connection Rev. F - 15 February, 2001 5 ALE/PROG P5.1 P2.5/A13 1 68 67 66 65 64 63 62 61 P5.2 2 P2.6/A14 3 P2.7/A15 4 PSEN NIC EA P0.6/AD6 5 NIC P0.5/AD5 6 NIC P5.3 7 P0.7/AD7 P0.4/AD4 8 60 59 58 57 56 55 54 53 52 51 50 49 P5.0 P2.4/A12 P2.3/A11 P4.7 P2.2/A10 P2.1/A9 P2.0/A8 P4.6 48 47 46 45 44 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 XTAL2 P3.7/RD P4.4 P3.6/WR P4.3 VSS P4.5 XTAL1 P3.5/T1 P3.4/T0 P3.2/INT0 P3.3/INT1 NIC P3.1/TxD NIC NIC NIC P3.0/RxD NIC NIC NIC NIC P0.4/AD4 P5.4 P5.3 P0.5/AD5 P0.6/AD6 P0.7/AD7 EA NIC ALE/PROG PSEN P2.7/A15 P2.6/A14 P5.2 P5.1 P2.5/A13 P5.0 RST PLCC 68 P1.5/CEX2 P1.2/ECI P1.3/CEX0 P4.1 P1.4/CEX1 P4.2 9 P1.7/CEX4 P0.3/AD3 P0.2/AD2 P5.6 P0.1/AD1 P0.0/AD0 P5.7 VCC VSS1 P1.0/T2 P4.0 P1.1/T2EX 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 P1.6/CEX3 P5.5 P5.4 T89C51RD2 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 1 48 2 47 3 46 4 45 5 44 6 43 7 42 8 41 9 40 10 39 11 38 12 37 13 36 14 35 15 34 16 33 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 VQFP64 1.4 P2.4/A12 P2.3/A11 P4.7 P2.2/A10 P2.1/A9 P2.0/A8 P4.6 NIC VSS P4.5 XTAL1 XTAL2 P3.7/RD P4.4 P3.6/WR P4.3 P4.2 P1.5/CEX2 P1.6/CEX3 P1.7/CEX4 RST NIC NIC NIC P3.0/RxD NIC NIC P3.1/TxD P3.2/INT0 P3.3/INT1 P3.4/T0 P3.5/T1 P5.5 P0.3/AD3 P0.2/AD2 P5.6 P0.1/AD1 P0.0/AD0 P5.7 VCC VSS1 P1.0/T2 P4.0 P1.1/T2EX P1.2/EC1 P1.3/CEX0 P4.1 P1.4/CEX1 NIC: No InternalConnection 6 Rev. F - 15 February, 2001 T89C51RD2 Pin Number Mnemonic Name and Function Type DIL LCC VQFP 1.4 20 22 16 I Ground: 0V reference 1 39 I Optional Ground: Contact the Sales Office for ground connection. 40 44 38 I Power Supply: This is the power supply voltage for normal, idle and powerdown operation P0.0-P0.7 39-32 43-36 37-30 I/O Port 0: Port 0 is an open-drain, bidirectional I/O port. Port 0 pins that have 1s written to them float and can be used as high impedance inputs. Port 0 must be polarized to VCC or VSS in order to prevent any parasitic current consumption. Port 0 is also the multiplexed low-order address and data bus during access to external program and data memory. In this application, it uses strong internal pull-up when emitting 1s. Port 0 also inputs the code bytes during EPROM programming. External pull-ups are required during program verification during which P0 outputs the code bytes. P1.0-P1.7 1-8 2-9 40-44 1-3 I/O Port 1: Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. Port 1 pins that have 1s written to them are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally pulled low will source current because of the internal pull-ups. Port 1 also receives the low-order address byte during memory programming and verification. Alternate functions for TSC8x54/58 Port 1 include: 1 2 40 I/O T2 (P1.0): Timer/Counter 2 external count input/Clockout 2 3 41 I T2EX (P1.1): Timer/Counter 2 Reload/Capture/Direction Control 3 4 42 I ECI (P1.2): External Clock for the PCA 4 5 43 I/O CEX0 (P1.3): Capture/Compare External I/O for PCA module 0 5 6 44 I/O CEX1 (P1.4): Capture/Compare External I/O for PCA module 1 6 7 1 I/O CEX2 (P1.5): Capture/Compare External I/O for PCA module 2 7 8 2 I/O CEX3 (P1.6): Capture/Compare External I/O for PCA module 3 VSS Vss1 VCC 8 9 3 I/O CEX4 (P1.7): Capture/Compare External I/O for PCA module 4 P2.0-P2.7 21-28 24-31 18-25 I/O Port 2: Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. Port 2 pins that have 1s written to them are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally pulled low will source current because of the internal pull-ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX @DPTR).In this application, it uses strong internal pull-ups emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @Ri), port 2 emits the contents of the P2 SFR. Some Port 2 pins receive the high order address bits during EPROM programming and verification: P2.0 to P2.5 for RB devices P2.0 to P2.6 for RC devices P2.0 to P2.7 for RD devices. P3.0-P3.7 10-17 11, 13-19 5, 7-13 I/O Port 3: Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. Port 3 pins that have 1s written to them are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally pulled low will source current because of the internal pull-ups. Port 3 also serves the special features of the 80C51 family, as listed below. 10 11 5 I RXD (P3.0): Serial input port 11 13 7 O TXD (P3.1): Serial output port 12 14 8 I INT0 (P3.2): External interrupt 0 13 15 9 I INT1 (P3.3): External interrupt 1 14 16 10 I T0 (P3.4): Timer 0 external input 15 17 11 I T1 (P3.5): Timer 1 external input 16 18 12 O WR (P3.6): External data memory write strobe Rev. F - 15 February, 2001 7 T89C51RD2 Pin Number Mnemonic Type Name and Function DIL LCC VQFP 1.4 17 19 13 O Reset 9 10 4 I/O Reset: A high on this pin for two machine cycles while the oscillator is running, resets the device. An internal diffused resistor to VSS permits a power-on reset using only an external capacitor to VCC. This pin is an output when the hardware watchdog forces a system reset. ALE/PROG 30 33 27 O (I) Address Latch Enable/Program Pulse: Output pulse for latching the low byte of the address during an access to external memory. In normal operation, ALE is emitted at a constant rate of 1/6 (1/3 in X2 mode) the oscillator frequency, and can be used for external timing or clocking. Note that one ALE pulse is skipped during each access to external data memory. This pin is also the program pulse input (PROG) during Flash programming. ALE can be disabled by setting SFR's AUXR.0 bit. With this bit set, ALE will be inactive during internal fetches. PSEN 29 32 26 O Program Store ENable: The read strobe to external program memory. When executing code from the external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory. PSEN is not activated during fetches from internal program memory. EA 31 35 29 I External Access Enable: EA must be externally held low to enable the device to fetch code from external program memory locations 0000H to FFFFH (RD). If security level 1 is programmed, EA will be internally latched on Reset. XTAL1 19 21 15 I Crystal 1: Input to the inverting oscillator amplifier and input to the internal clock generator circuits. XTAL2 18 20 14 O Crystal 2: Output from the inverting oscillator amplifier 8 RD (P3.7): External data memory read strobe Rev. F - 15 February, 2001 T89C51RD2 5.1. Pin Description for 64/68 pin Packages Port 4 and Port 5 are 8-bit bidirectional I/O ports with internal pull-ups. Pins that have 1 written to them are pulled high by the internal pull ups and can be used as inputs. As inputs, pins that are externally pulled low will source current because of the internal pull-ups. Refer to the previous pin description for other pins. VSS VCC P0.0 P0.1 P0.2 P0.3 P0.4 P0.5 P0.6 P0.7 P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 P3.0 P3.1 P3.2 P3.3 P3.4 P3.5 P3.6 P3.7 RESET ALE/PROG PSEN EA XTAL1 XTAL2 P4.0 P4.1 P4.2 P4.3 P4.4 P4.5 P4.6 P4.7 P5.0 P5.1 P5.2 P5.3 P5.4 P5.5 P5.6 P5.7 PLCC68 SQUARE VQFP64 1.4 51, 18 17 15 14 12 11 9 6 5 3 19 21 22 23 25 27 28 29 54 55 56 58 59 61 64 65 34 39 40 41 42 43 45 47 30 68 67 2 49 48 20 24 26 44 46 50 53 57 60 62 63 7 8 10 13 16 9/40 8 6 5 3 2 64 61 60 59 10 12 13 14 16 18 19 20 43 44 45 47 48 50 53 54 25 28 29 30 31 32 34 36 21 56 55 58 38 37 11 15 17 33 35 39 42 46 49 51 52 62 63 1 4 7 Rev. F - 15 February, 2001 9 T89C51RD2 6. Enhanced Features In comparison to the original 80C52, the T89C51RD2 implements some new features, which are: * * * * * * * * * * The X2 option. The Dual Data Pointer. The extended RAM. The Programmable Counter Array (PCA). The Watchdog. The 4 level interrupt priority system. The power-off flag. The ONCE mode. The ALE disabling. Some enhanced features are also located in the UART and the timer 2. 6.1. X2 Feature and Clock Generation The T89C51RD2 core needs only 6 clock periods per machine cycle. This feature called "X2" provides the following advantages: * * * * Divide frequency crystals by 2 (cheaper crystals) while keeping same CPU power. Save power consumption while keeping same CPU power (oscillator power saving). Save power consumption by dividing dynamically operating frequency by 2 in operating and idle modes. Increase CPU power by 2 while keeping same crystal frequency. In order to keep the original C51 compatibility, a divider by 2 is inserted between the XTAL1 signal and the main clock input of the core (phase generator). This divider may be disabled by software. 6.1.1. Description The clock for the whole circuit and peripheral is first divided by two before being used by the CPU core and peripherals. This allows any cyclic ratio to be accepted on XTAL1 input. In X2 mode, as this divider is bypassed, the signals on XTAL1 must have a cyclic ratio between 40 to 60%. Figure 1. shows the clock generation block diagram. X2 bit is validated on XTAL1/2 rising edge to avoid glitches when switching from X2 to STD mode. Figure 2. shows the mode switching waveforms. 2 XTAL1 FXTAL XTAL1:2 0 1 state machine: 6 clock cycles. CPU control FOSC X2 CKCON reg Figure 1. Clock Generation Diagram Rev. F - 15 February, 2001 10 T89C51RD2 XTAL1 XTAL1:2 X2 bit CPU clock STD Mode X2 Mode STD Mode Figure 2. Mode Switching Waveforms The X2 bit in the CKCON register (See Table 2.) allows to switch from 12 clock periods per instruction to 6 clock periods and vice versa. At reset, the standard speed is activated (STD mode). Setting this bit activates the X2 feature (X2 mode). The T0X2, T1X2, T2X2, SiX2, PcaX2 and WdX2 bits in the CKCON register (See Table 2.) allow to switch from standard peripheral speed (12 clock periods per peripheral clock cycle) to fast peripheral speed (6 clock periods per peripheral clock cycle). These bits are active only in X2 mode. More information about the X2 mode can be found in the application note ANM072 "How to take advantage of the X2 features in TS80C51 microcontroller?" Table 2. CKCON Register CKCON - Clock Control Register (8Fh) 7 6 5 4 3 2 1 0 - WdX2 PcaX2 SiX2 T2X2 T1X2 T0X2 X2 Bit Number Bit Mnemonic 7 - 6 WdX2 Watchdog clock (This control bit is validated when the CPU clock X2 is set; when X2 is low, this bit has no effect) Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. 5 PcaX2 Programmable Counter Array clock (This control bit is validated when the CPU clock X2 is set; when X2 is low, this bit has no effect) Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. 4 SiX2 Enhanced UART clock (Mode 0 and 2) (This control bit is validated when the CPU clock X2 is set; when X2 is low, this bit has no effect) Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. 3 T2X2 Timer2 clock (This control bit is validated when the CPU clock X2 is set; when X2 is low, this bit has no effect) Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. 2 T1X2 Timer1 clock (This control bit is validated when the CPU clock X2 is set; when X2 is low, this bit has no effect) Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle 11 Description Reserved Rev. F - 15 February, 2001 T89C51RD2 Bit Number Bit Mnemonic Description 1 T0X2 Timer0 clock (This control bit is validated when the CPU clock X2 is set; when X2 is low, this bit has no effect) Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle 0 X2 CPU clock Clear to select 12 clock periods per machine cycle (STD mode) for CPU and all the peripherals. Set to select 6clock periods per machine cycle (X2 mode) and to enable the individual peripherals "X2" bits. Reset Value = X000 0000b Not bit addressable Rev. F - 15 February, 2001 12 T89C51RD2 6.2. Dual Data Pointer Register Ddptr The additional data pointer can be used to speed up code execution and reduce code size. The dual DPTR structure is a way by which the chip will specify the address of an external data memory location. There are two 16-bit DPTR registers that address the external memory, and a single bit called DPS = AUXR1/bit0 (See Table 3.) that allows the program code to switch between them (Refer to Figure 3). External Data Memory 7 0 DPS DPTR1 DPTR0 AUXR1(A2H) DPH(83H) DPL(82H) Figure 3. Use of Dual Pointer Table 3. AUXR1: Auxiliary Register 1 AUXR1 Address 0A2H Reset value Symbol DPS GF3 a. b. - - - - GF3 0 - DPS X X X X 0 0 X 0 Function Not implemented, reserved for future use.a Data Pointer Selection. DPS Operating Mode 0 DPTR0 Selected 1 DPTR1 Selected This bit is a general purpose user flagb. User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new feature. In that case, the reset value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate. Bit 2 stuck at 0; this allows to use INC AUXR1 to toggle DPS without changing GF3. Application Software can take advantage of the additional data pointers to both increase speed and reduce code size, for example, block operations (copy, compare, search ...) are well served by using one data pointer as a 'source' pointer and the other one as a "destination" pointer. ASSEMBLY LANGUAGE Rev. F - 15 February, 2001 13 T89C51RD2 ; Block move using dual data pointers ; Modifies DPTR0, DPTR1, A and PSW ; note: DPS exits opposite of entry state ; unless an extra INC AUXR1 is added ; 00A2 AUXR1 EQU 0A2H ; 0000 909000MOV DPTR,#SOURCE ; address of SOURCE 0003 05A2 INC AUXR1 ; switch data pointers 0005 90A000 MOV DPTR,#DEST ; address of DEST 0008 LOOP: 0008 05A2 INC AUXR1 ; switch data pointers 000A E0 MOVX A,@DPTR ; get a byte from SOURCE 000B A3 INC DPTR ; increment SOURCE address 000C 05A2 INC AUXR1 ; switch data pointers 000E F0 MOVX @DPTR,A ; write the byte to DEST 000F A3 INC DPTR ; increment DEST address 0010 70F6JNZ LOOP ; check for 0 terminator 0012 05A2 INC AUXR1 ; (optional) restore DPS INC is a short (2 bytes) and fast (12 clocks) way to manipulate the DPS bit in the AUXR1 SFR. However, note that the INC instruction does not directly force the DPS bit to a particular state, but simply toggles it. In simple routines, such as the block move example, only the fact that DPS is toggled in the proper sequence matters, not its actual value. In other words, the block move routine works the same whether DPS is '0' or '1' on entry. Observe that without the last instruction (INC AUXR1), the routine will exit with DPS in the opposite state. 14 Rev. F - 15 February, 2001 T89C51RD2 6.3. Expanded RAM (XRAM) The T89C51RD2 provide additional Bytes of random access memory (RAM) space for increased data parameter handling and high level language usage. T89C51RD2 devices have expanded RAM in external data space; Maximum size and location are described in Table 4. Table 4. Description of expanded RAM Port Address XRAM size T89C51RD2 1024 Start End 00h 3FFh The T89C51RD2 has internal data memory that is mapped into four separate segments. The four segments are: * * * * 1. The Lower 128 bytes of RAM (addresses 00H to 7FH) are directly and indirectly addressable. 2. The Upper 128 bytes of RAM (addresses 80H to FFH) are indirectly addressable only. 3. The Special Function Registers, SFRs, (addresses 80H to FFH) are directly addressable only. 4. The expanded RAM bytes are indirectly accessed by MOVX instructions, and with the EXTRAM bit cleared in the AUXR register. (See ) The Lower 128 bytes can be accessed by either direct or indirect addressing. The Upper 128 bytes can be accessed by indirect addressing only. The Upper 128 bytes occupy the same address space as the SFR. That means they have the same address, but are physically separate from SFR space. FF or 3FF FF FF Upper 128 bytes Internal Ram indirect accesses XRAM 80 00 Special Function Register direct accesses External Data Memory 80 Lower 128 bytes Internal Ram direct or indirect accesses 00 FFFF 0100 or 0400 0000 Figure 4. Internal and External Data Memory Address When an instruction accesses an internal location above address 7FH, the CPU knows whether the access is to the upper 128 bytes of data RAM or to SFR space by the addressing mode used in the instruction. * Instructions that use direct addressing access SFR space. For example: MOV 0A0H, # data ,accesses the SFR at location 0A0H (which is P2). * Instructions that use indirect addressing access the Upper 128 bytes of data RAM. For example: MOV @R0, # data where R0 contains 0A0H, accesses the data byte at address 0A0H, rather than P2 (whose address is 0A0H). Rev. F - 15 February, 2001 15 T89C51RD2 * The XRAM bytes can be accessed by indirect addressing, with EXTRAM bit cleared and MOVX instructions. This part of memory which is physically located on-chip, logically occupies the first bytes of external data memory. The bits XRS0 and XRS1 are used to hide a part of the available XRAM as explained in Table . This can be useful if external peripherals are mapped at addresses already used by the internal XRAM. * With EXTRAM = 0, the XRAM is indirectly addressed, using the MOVX instruction in combination with any of the registers R0, R1 of the selected bank or DPTR. An access to XRAM will not affect ports P0, P2, P3.6 (WR) and P3.7 (RD). For example, with EXTRAM = 0, MOVX @R0, # data where R0 contains 0A0H, accesses the XRAM at address 0A0H rather than external memory. An access to external data memory locations higher than the accessible size of the XRAM will be performed with the MOVX DPTR instructions in the same way as in the standard 80C51, so with P0 and P2 as data/address busses, and P3.6 and P3.7 as write and read timing signals. Accesses to XRAM above 0FFH can only be done thanks to the use of DPTR. * With EXTRAM = 1, MOVX @Ri and MOVX @DPTR will be similar to the standard 80C51. MOVX @ Ri will provide an eight-bit address multiplexed with data on Port0 and any output port pins can be used to output higher order address bits. This is to provide the external paging capability. MOVX @DPTR will generate a sixteen-bit address. Port2 outputs the high-order eight address bits (the contents of DPH) while Port0 multiplexes the low-order eight address bits (DPL) with data. MOVX @ Ri and MOVX @DPTR will generate either read or write signals on P3.6 (WR) and P3.7 (RD). The stack pointer (SP) may be located anywhere in the 256 bytes RAM (lower and upper RAM) internal data memory. The stack may not be located in the XRAM. The M0 bit allows to stretch the XRAM timings; if M0 is set, the read and write pulses are extended from 6 to 30 clock periods. This is useful to access external slow peripherals. Auxiliary Register AUXR AUXR Address 08EH Reset value - - M0 - XRS1 XRS0 EXTRAM AO X X 0 X 1 0 0 0 Symbol AO EXTRAM XRS0 XRS1 M0 a. 16 Function Not implemented, reserved for future use.a Disable/Enable ALE AO Operating Mode 0 ALE is emitted at a constant rate of 1/6 the oscillator frequency (or 1/3 if X2 mode is used) 1 ALE is active only during a MOVX or MOVC instruction Internal/External RAM (00H-FFH) access using MOVX @ Ri/ @ DPTR EXTRAM Operating Mode 0 Internal XRAM access using MOVX @ Ri/ @ DPTR 1 External data memory access XRAM size: Accessible size of the XRAM XRS1:0 XRAM size 00 256 bytes 01 512 bytes 10 768 bytes (default) 11 1024 bytes Stretch MOVX control: the RD/ and the WR/ pulse length is increased according to the value of M0 M0 Pulse length in clock period 0 6 1 30 User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features. In that case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate. Rev. F - 15 February, 2001 T89C51RD2 6.4. Timer 2 The timer 2 in the T89C51RD2 is compatible with the timer 2 in the 80C52. It is a 16-bit timer/counter: the count is maintained by two eight-bit timer registers, TH2 and TL2, connected in cascade. It is controlled by T2CON register (See Table 5) and T2MOD register (See Table 6). Timer 2 operation is similar to Timer 0 and Timer 1. C/T2 selects FOSC/12 (timer operation) or external pin T2 (counter operation) as the timer clock input. Setting TR2 allows TL2 to be incremented by the selected input. Timer 2 has 3 operating modes: capture, autoreload and Baud Rate Generator. These modes are selected by the combination of RCLK, TCLK and CP/RL2 (T2CON), as described in the ATMEL Wireless and Micrcontrollers 8-bit Microcontroller Hardware description. Refer to the ATMEL Wireless and Micrcontrollers 8-bit Microcontroller Hardware description for the description of Capture and Baud Rate Generator Modes. In T89C51RD2 Timer 2 includes the following enhancements: * Auto-reload mode with up or down counter * Programmable clock-output 6.4.1. Auto-Reload Mode The auto-reload mode configures timer 2 as a 16-bit timer or event counter with automatic reload. If DCEN bit in T2MOD is cleared, timer 2 behaves as in 80C52 (refer to the ATMEL Wireless and Micrcontrollers 8-bit Microcontroller Hardware description). If DCEN bit is set, timer 2 acts as an Up/down timer/counter as shown in Figure 5. In this mode the T2EX pin controls the direction of count. When T2EX is high, timer 2 counts up. Timer overflow occurs at FFFFh which sets the TF2 flag and generates an interrupt request. The overflow also causes the 16-bit value in RCAP2H and RCAP2L registers to be loaded into the timer registers TH2 and TL2. When T2EX is low, timer 2 counts down. Timer underflow occurs when the count in the timer registers TH2 and TL2 equals the value stored in RCAP2H and RCAP2L registers. The underflow sets TF2 flag and reloads FFFFh into the timer registers. The EXF2 bit toggles when timer 2 overflows or underflows according to the the direction of the count. EXF2 does not generate any interrupt. This bit can be used to provide 17-bit resolution. Rev. F - 15 February, 2001 17 T89C51RD2 XTAL1 FXTAL :12 FOSC 0 1 T2 C/T2 T2CONreg TR2 T2CONreg (DOWN COUNTING RELOAD VALUE) FFh FFh (8-bit) (8-bit) T2EX: if DCEN=1, 1=UP if DCEN=1, 0=DOWN if DCEN = 0, up counting TOGGLE T2CONreg EXF2 TL2 TH2 (8-bit) (8-bit) TF2 TIMER 2 INTERRUPT T2CONreg RCAP2L (8-bit) RCAP2H (8-bit) (UP COUNTING RELOAD VALUE) Figure 5. Auto-Reload Mode Up/Down Counter (DCEN = 1) 6.4.2. Programmable Clock-Output In the clock-out mode, timer 2 operates as a 50%-duty-cycle, programmable clock generator (See Figure 6) . The input clock increments TL2 at frequency FOSC/2. The timer repeatedly counts to overflow from a loaded value. At overflow, the contents of RCAP2H and RCAP2L registers are loaded into TH2 and TL2. In this mode, timer 2 overflows do not generate interrupts. The formula gives the clock-out frequency as a function of the system oscillator frequency and the value in the RCAP2H and RCAP2L registers : F osc Clock - OutFrequency = -------------------------------------------------------------------------------------4 x ( 65536 - RCAP2H RCAP2L ) For a 16 MHz system clock, timer 2 has a programmable frequency range of 61 Hz (FOSC/216) to 4 MHz (FOSC/4). The generated clock signal is brought out to T2 pin (P1.0). Timer 2 is programmed for the clock-out mode as follows: * * * * Set T2OE bit in T2MOD register. Clear C/T2 bit in T2CON register. Determine the 16-bit reload value from the formula and enter it in RCAP2H/RCAP2L registers. Enter a 16-bit initial value in timer registers TH2/TL2. It can be the same as the reload value or a different one depending on the application. * To start the timer, set TR2 run control bit in T2CON register. 18 Rev. F - 15 February, 2001 T89C51RD2 It is possible to use timer 2 as a baud rate generator and a clock generator simultaneously. For this configuration, the baud rates and clock frequencies are not independent since both functions use the values in the RCAP2H and RCAP2L registers. XTAL1 :2 TR2 T2CON reg TL2 (8-bit) TH2 (8-bit) OVEFLOW RCAP2L RCAP2H (8-bit) (8-bit) Toggle T2 Q D T2OE T2MOD reg T2EX EXF2 EXEN2 T2CON reg TIMER 2 INTERRUPT T2CON reg Figure 6. Clock-Out Mode C/T2 = 0 Rev. F - 15 February, 2001 19 T89C51RD2 Table 5. T2CON Register T2CON - Timer 2 Control Register (C8h) 7 6 5 4 3 2 1 0 TF2 EXF2 RCLK TCLK EXEN2 TR2 C/T2# CP/RL2# Bit Number Bit Mnemonic 7 TF2 6 EXF2 Timer 2 External Flag Set when a capture or a reload is caused by a negative transition on T2EX pin if EXEN2=1. When set, causes the CPU to vector to timer 2 interrupt routine when timer 2 interrupt is enabled. Must be cleared by software. EXF2 doesn't cause an interrupt in Up/down counter mode (DCEN = 1) 5 RCLK Receive Clock bit Clear to use timer 1 overflow as receive clock for serial port in mode 1 or 3. Set to use timer 2 overflow as receive clock for serial port in mode 1 or 3. 4 TCLK Transmit Clock bit Clear to use timer 1 overflow as transmit clock for serial port in mode 1 or 3. Set to use timer 2 overflow as transmit clock for serial port in mode 1 or 3. 3 EXEN2 Timer 2 External Enable bit Clear to ignore events on T2EX pin for timer 2 operation. Set to cause a capture or reload when a negative transition on T2EX pin is detected, if timer 2 is not used to clock the serial port. 2 TR2 1 C/T2# 0 CP/RL2# Description Timer 2 overflow Flag Must be cleared by software. Set by hardware on timer 2 overflow, if RCLK = 0 and TCLK = 0. Timer 2 Run control bit Clear to turn off timer 2. Set to turn on timer 2. Timer/Counter 2 select bit Clear for timer operation (input from internal clock system: FOSC). Set for counter operation (input from T2 input pin, falling edge trigger). Must be 0 for clock out mode. Timer 2 Capture/Reload bit If RCLK=1 or TCLK=1, CP/RL2# is ignored and timer is forced to auto-reload on timer 2 overflow. Clear to auto-reload on timer 2 overflows or negative transitions on T2EX pin if EXEN2=1. Set to capture on negative transitions on T2EX pin if EXEN2=1. Reset Value = 0000 0000b Bit addressable 20 Rev. F - 15 February, 2001 T89C51RD2 Table 6. T2MOD Register T2MOD - Timer 2 Mode Control Register (C9h) 7 6 5 4 3 2 1 0 - - - - - - T2OE DCEN Bit Number Bit Mnemonic 7 - Reserved The value read from this bit is indeterminate. Do not set this bit. 6 - Reserved The value read from this bit is indeterminate. Do not set this bit. 5 - Reserved The value read from this bit is indeterminate. Do not set this bit. 4 - Reserved The value read from this bit is indeterminate. Do not set this bit. 3 - Reserved The value read from this bit is indeterminate. Do not set this bit. 2 - Reserved The value read from this bit is indeterminate. Do not set this bit. 1 T2OE Timer 2 Output Enable bit Clear to program P1.0/T2 as clock input or I/O port. Set to program P1.0/T2 as clock output. 0 DCEN Down Counter Enable bit Clear to disable timer 2 as up/down counter. Set to enable timer 2 as up/down counter. Description Reset Value = XXXX XX00b Not bit addressable Rev. F - 15 February, 2001 21 T89C51RD2 6.5. Programmable Counter Array PCA The PCA provides more timing capabilities with less CPU intervention than the standard timer/counters. Its advantages include reduced software overhead and improved accuracy. The PCA consists of a dedicated timer/ counter which serves as the time base for an array of five compare/ capture modules. Its clock input can be programmed to count any one of the following signals: * * * * Oscillator frequency / 12 (/ 6 in X2 mode) Oscillator frequency / 4 (/ 2 in X2 mode) Timer 0 overflow External input on ECI (P1.2) Each compare/capture modules can be programmed in any one of the following modes: * * * * rising and/or falling edge capture, software timer, high-speed output, or pulse width modulator. Module 4 can also be programmed as a watchdog timer (See Section "PCA Watchdog Timer", page 31). When the compare/capture modules are programmed in the capture mode, software timer, or high speed output mode, an interrupt can be generated when the module executes its function. All five modules plus the PCA timer overflow share one interrupt vector. The PCA timer/counter and compare/capture modules share Port 1 for external I/O. These pins are listed below. If the port is not used for the PCA, it can still be used for standard I/O. PCA component External I/O Pin 16-bit Counter P1.2 / ECI 16-bit Module 0 P1.3 / CEX0 16-bit Module 1 P1.4 / CEX1 16-bit Module 2 P1.5 / CEX2 16-bit Module 3 P1.6 / CEX3 16-bit Module 4 P1.7 / CEX4 The PCA timer is a common time base for all five modules (See Figure 7). The timer count source is determined from the CPS1 and CPS0 bits in the CMOD SFR (See Table 7) and can be programmed to run at: * * * * 1/12 the oscillator frequency. (Or 1/6 in X2 Mode) 1/4 the oscillator frequency. (Or 1/2 in X2 Mode) The Timer 0 overflow The input on the ECI pin (P1.2) Rev. F - 15 February, 2001 22 T89C51RD2 To PCA modules Fosc /12 overflow Fosc / 4 CH T0 OVF It CL 16 bit up/down counter P1.2 CIDL WDTE CF CR CPS1 CPS0 ECF CMOD 0xD9 CCF2 CCF1 CCF0 CCON 0xD8 Idle CCF4 CCF3 Figure 7. PCA Timer/Counter Table 7. CMOD: PCA Counter Mode Register CMOD Address 0D9H Reset value Symbol CIDL WDTE - - - CPS1 CPS0 ECF 0 0 X X X 0 0 0 Function CIDL Counter Idle control: CIDL = 0 programs the PCA Counter to continue functioning during idle Mode. CIDL = 1 programs it to be gated off during idle. WDTE Watchdog Timer Enable: WDTE = 0 disables Watchdog Timer function on PCA Module 4. WDTE = 1 enables it. - Not implemented, reserved for future use.a CPS1 PCA Count Pulse Select bit 1. CPS0 PCA Count Pulse Select bit 0. ECF a. b. Selected PCA input.b CPS1 CPS0 0 0 0 1 Internal clock fosc/12 ( Or fosc/6 in X2 Mode). Internal clock fosc/4 ( Or fosc/2 in X2 Mode). 1 0 Timer 0 Overflow 1 1 External clock at ECI/P1.2 pin (max rate = fosc/ 8) PCA Enable Counter Overflow interrupt: ECF = 1 enables CF bit in CCON to generate an interrupt. ECF = 0 disables that function of CF. User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features. In that case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate. fosc = oscillator frequency The CMOD SFR includes three additional bits associated with the PCA (See Figure 7 and Table 7). * The CIDL bit which allows the PCA to stop during idle mode. * The WDTE bit which enables or disables the watchdog function on module 4. 23 Rev. F - 15 February, 2001 T89C51RD2 * The ECF bit which when set causes an interrupt and the PCA overflow flag CF (in the CCON SFR) to be set when the PCA timer overflows. The CCON SFR contains the run control bit for the PCA and the flags for the PCA timer (CF) and each module (Refer to Table 8). * Bit CR (CCON.6) must be set by software to run the PCA. The PCA is shut off by clearing this bit. * Bit CF: The CF bit (CCON.7) is set when the PCA counter overflows and an interrupt will be generated if the ECF bit in the CMOD register is set. The CF bit can only be cleared by software. * Bits 0 through 4 are the flags for the modules (bit 0 for module 0, bit 1 for module 1, etc.) and are set by hardware when either a match or a capture occurs. These flags also can only be cleared by software. Table 8. CCON: PCA Counter Control Register CCON Address 0D8H Reset value Symbol CF CR - CCF4 CCF3 CCF2 CCF1 CCF0 0 0 X 0 0 0 0 0 Function CF PCA Counter Overflow flag. Set by hardware when the counter rolls over. CF flags an interrupt if bit ECF in CMOD is set. CF may be set by either hardware or software but can only be cleared by software. CR PCA Counter Run control bit. Set by software to turn the PCA counter on. Must be cleared by software to turn the PCA counter off. - Not implemented, reserved for future use.a CCF4 PCA Module 4 interrupt flag. Set by hardware when a match or capture occurs. Must be cleared by software. CCF3 PCA Module 3 interrupt flag. Set by hardware when a match or capture occurs. Must be cleared by software. CCF2 PCA Module 2 interrupt flag. Set by hardware when a match or capture occurs. Must be cleared by software. CCF1 PCA Module 1 interrupt flag. Set by hardware when a match or capture occurs. Must be cleared by software. CCF0 PCA Module 0 interrupt flag. Set by hardware when a match or capture occurs. Must be cleared by software. a. User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features. In that case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate. The watchdog timer function is implemented in module 4 (See Figure 10). The PCA interrupt system is shown in Figure 8 Rev. F - 15 February, 2001 24 T89C51RD2 CF CR CCF4 CCF3 CCF2 CCF1 CCF0 CCON 0xD8 PCA Timer/Counter Module 0 Module 1 To Interrupt priority decoder Module 2 Module 3 Module 4 CMOD.0 ECF ECCFn CCAPMn.0 IE.6 EC IE.7 EA Figure 8. PCA Interrupt System PCA Modules: each one of the five compare/capture modules has six possible functions. It can perform: * * * * * * 16-bit Capture, positive-edge triggered, 16-bit Capture, negative-edge triggered, 16-bit Capture, both positive and negative-edge triggered, 16-bit Software Timer, 16-bit High Speed Output, 8-bit Pulse Width Modulator. In addition, module 4 can be used as a Watchdog Timer. Each module in the PCA has a special function register associated with it. These registers are: CCAPM0 for module 0, CCAPM1 for module 1, etc. (See Table 9). The registers contain the bits that control the mode that each module will operate in. * The ECCF bit (CCAPMn.0 where n=0, 1, 2, 3, or 4 depending on the module) enables the CCF flag in the CCON SFR to generate an interrupt when a match or compare occurs in the associated module. * PWM (CCAPMn.1) enables the pulse width modulation mode. * The TOG bit (CCAPMn.2) when set causes the CEX output associated with the module to toggle when there is a match between the PCA counter and the module's capture/compare register. * The match bit MAT (CCAPMn.3) when set will cause the CCFn bit in the CCON register to be set when there is a match between the PCA counter and the module's capture/compare register. * The next two bits CAPN (CCAPMn.4) and CAPP (CCAPMn.5) determine the edge that a capture input will be active on. The CAPN bit enables the negative edge, and the CAPP bit enables the positive edge. If both bits are set both edges will be enabled and a capture will occur for either transition. * The last bit in the register ECOM (CCAPMn.6) when set enables the comparator function. Table 10 shows the CCAPMn settings for the various PCA functions. . 25 Rev. F - 15 February, 2001 T89C51RD2 Table 9. CCAPMn: PCA Modules Compare/Capture Control Registers CCAPM0=0DAH CCAPM1=0DBH CCAPM2=0DCH CCAPM3=0DDH CCAPM4=0DEH CCAPMn Address n=0-4 Reset value Symbol - ECOMn CAPPn CAPNn MATn TOGn PWMm ECCFn X 0 0 0 0 0 0 0 Function - Not implemented, reserved for future use.a ECOMn Enable Comparator. ECOMn = 1 enables the comparator function. CAPPn Capture Positive, CAPPn = 1 enables positive edge capture. CAPNn Capture Negative, CAPNn = 1 enables negative edge capture. MATn Match. When MATn = 1, a match of the PCA counter with this module's compare/capture register causes the CCFn bit in CCON to be set, flagging an interrupt. TOGn Toggle. When TOGn = 1, a match of the PCA counter with this module's compare/capture register causes the CEXn pin to toggle. PWMn Pulse Width Modulation Mode. PWMn = 1 enables the CEXn pin to be used as a pulse width modulated output. ECCFn Enable CCF interrupt. Enables compare/capture flag CCFn in the CCON register to generate an interrupt. a. User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features. In that case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate. Table 10. PCA Module Modes (CCAPMn Registers) ECOMn CAPPn CAPNn MATn TOGn PWMm ECCFn 0 0 0 0 0 0 0 Module Function No Operation X 1 0 0 0 0 X 16-bit capture by a positive-edge trigger on CEXn X 0 1 0 0 0 X 16-bit capture by a negative trigger on CEXn X 1 1 0 0 0 X 16-bit capture by a transition on CEXn 1 0 0 1 0 0 X 16-bit Software Timer / Compare mode. 1 0 0 1 1 0 X 16-bit High Speed Output 1 0 0 0 0 1 0 8-bit PWM 1 0 0 1 X 0 X Watchdog Timer (module 4 only) There are two additional registers associated with each of the PCA modules. They are CCAPnH and CCAPnL and these are the registers that store the 16-bit count when a capture occurs or a compare should occur. When a module is used in the PWM mode these registers are used to control the duty cycle of the output (See Table 11 & Table 12) Rev. F - 15 February, 2001 26 T89C51RD2 Table 11. CCAPnH: PCA Modules Capture/Compare Registers High CCAPnH Address n=0-4 CCAP0H=0FAH CCAP1H=0FBH CCAP2H=0FCH CCAP3H=0FDH CCAP4H=0FEH Reset value 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 Table 12. CCAPnL: PCA Modules Capture/Compare Registers Low CCAPnL Address n=0-4 CCAP0L=0EAH CCAP1L=0EBH CCAP2L=0ECH CCAP3L=0EDH CCAP4L=0EEH Reset value 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 Table 13. CH: PCA Counter High CH Address 0F9H Reset value 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 Table 14. CL: PCA Counter Low CL Address 0E9H Reset value 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 6.5.1. PCA Capture Mode To use one of the PCA modules in the capture mode either one or both of the CCAPM bits CAPN and CAPP for that module must be set. The external CEX input for the module (on port 1) is sampled for a transition. When a valid transition occurs the PCA hardware loads the value of the PCA counter registers (CH and CL) into the module's capture registers (CCAPnL and CCAPnH). If the CCFn bit for the module in the CCON SFR and the ECCFn bit in the CCAPMn SFR are set then an interrupt will be generated (Refer to Figure 9). 27 Rev. F - 15 February, 2001 T89C51RD2 CF CR CCF4 CCF3 CCF2 CCF1 CCF0 CCON 0xD8 PCA IT PCA Counter/Timer Cex.n CH CL CCAPnH CCAPnL Capture ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CCAPMn, n= 0 to 4 0xDA to 0xDE Figure 9. PCA Capture Mode 6.5.2. 16-bit Software Timer / Compare Mode The PCA modules can be used as software timers by setting both the ECOM and MAT bits in the modules CCAPMn register. The PCA timer will be compared to the module's capture registers and when a match occurs an interrupt will occur if the CCFn (CCON SFR) and the ECCFn (CCAPMn SFR) bits for the module are both set (See Figure 10). Rev. F - 15 February, 2001 28 T89C51RD2 CF Write to CCAPnL CR CCF4 CCF3 CCF2 CCF1 CCF0 CCON 0xD8 Reset PCA IT Write to CCAPnH 1 CCAPnH 0 CCAPnL Enable Match 16 bit comparator CH RESET * CL PCA counter/timer ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CIDL WDTE CPS1 CPS0 ECF CCAPMn, n = 0 to 4 0xDA to 0xDE CMOD 0xD9 * Only for Module 4 Figure 10. PCA Compare Mode and PCA Watchdog Timer Before enabling ECOM bit, CCAPnL and CCAPnH should be set with a non zero value, otherwise an unwanted match could happen. Writing to CCAPnH will set the ECOM bit. Once ECOM set, writing CCAPnL will clear ECOM so that an unwanted match doesn't occur while modifying the compare value. Writing to CCAPnH will set ECOM. For this reason, user software should write CCAPnL first, and then CCAPnH. Of course, the ECOM bit can still be controlled by accessing to CCAPMn register. 6.5.3. High Speed Output Mode In this mode the CEX output (on port 1) associated with the PCA module will toggle each time a match occurs between the PCA counter and the module's capture registers. To activate this mode the TOG, MAT, and ECOM bits in the module's CCAPMn SFR must be set (See Figure 11). A prior write must be done to CCAPnL and CCAPnH before writing the ECOMn bit. 29 Rev. F - 15 February, 2001 T89C51RD2 CF Write to CCAPnL CR CCF4 CCF3 CCF2 CCF1 CCF0 CCON 0xD8 Reset PCA IT Write to CCAPnH 1 CCAPnH 0 CCAPnL Enable 16 bit comparator CH Match CL CEXn PCA counter/timer ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CCAPMn, n = 0 to 4 0xDA to 0xDE Figure 11. PCA High Speed Output Mode Before enabling ECOM bit, CCAPnL and CCAPnH should be set with a non zero value, otherwise an unwanted match could happen. Once ECOM set, writing CCAPnL will clear ECOM so that an unwanted match doesn't occur while modifying the compare value. Writing to CCAPnH will set ECOM. For this reason, user software should write CCAPnL first, and then CCAPnH. Of course, the ECOM bit can still be controlled by accessing to CCAPMn register. 6.5.4. Pulse Width Modulator Mode All of the PCA modules can be used as PWM outputs. Figure 12 shows the PWM function. The frequency of the output depends on the source for the PCA timer. All of the modules will have the same frequency of output because they all share the PCA timer. The duty cycle of each module is independently variable using the module's capture register CCAPLn. When the value of the PCA CL SFR is less than the value in the module's CCAPLn Rev. F - 15 February, 2001 30 T89C51RD2 SFR the output will be low, when it is equal to or greater than the output will be high. When CL overflows from FF to 00, CCAPLn is reloaded with the value in CCAPHn. This allows updating the PWM without glitches. The PWM and ECOM bits in the module's CCAPMn register must be set to enable the PWM mode. CCAPnH Overflow CCAPnL "0" Enable 8 bit comparator CEXn < "1" CL PCA counter/timer ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CCAPMn, n= 0 to 4 0xDA to 0xDE Figure 12. PCA PWM Mode 6.5.5. PCA Watchdog Timer An on-board watchdog timer is available with the PCA to improve the reliability of the system without increasing chip count. Watchdog timers are useful for systems that are susceptible to noise, power glitches, or electrostatic discharge. Module 4 is the only PCA module that can be programmed as a watchdog. However, this module can still be used for other modes if the watchdog is not needed. Figure 10 shows a diagram of how the watchdog works. The user pre-loads a 16-bit value in the compare registers. Just like the other compare modes, this 16-bit value is compared to the PCA timer value. If a match is allowed to occur, an internal reset will be generated. This will not cause the RST pin to be driven high. In order to hold off the reset, the user has three options: * 1. periodically change the compare value so it will never match the PCA timer, * 2. periodically change the PCA timer value so it will never match the compare values, or * 3. disable the watchdog by clearing the WDTE bit before a match occurs and then re-enable it. The first two options are more reliable because the watchdog timer is never disabled as in option #3. If the program counter ever goes astray, a match will eventually occur and cause an internal reset. The second option is also not recommended if other PCA modules are being used. Remember, the PCA timer is the time base for all modules; changing the time base for other modules would not be a good idea. Thus, in most applications the first solution is the best option. This watchdog timer won't generate a reset out on the reset pin. 31 Rev. F - 15 February, 2001 T89C51RD2 6.6. Serial I/O Port The serial I/O port in the T89C51RD2 is compatible with the serial I/O port in the 80C52. It provides both synchronous and asynchronous communication modes. It operates as an Universal Asynchronous Receiver and Transmitter (UART) in three full-duplex modes (Modes 1, 2 and 3). Asynchronous transmission and reception can occur simultaneously and at different baud rates Serial I/O port includes the following enhancements: * Framing error detection * Automatic address recognition 6.6.1. Framing Error Detection Framing bit error detection is provided for the three asynchronous modes (modes 1, 2 and 3). To enable the framing bit error detection feature, set SMOD0 bit in PCON register (See Figure 13). SM0/FE SM1 SM2 REN TB8 RB8 TI RI SCON (98h) Set FE bit if stop bit is 0 (framing error) (SMOD0 = 1) SM0 to UART mode control (SMOD0 = 0) SMOD1 SMOD0 - POF GF1 GF0 PD IDL PCON (87h) To UART framing error control Figure 13. Framing Error Block Diagram When this feature is enabled, the receiver checks each incoming data frame for a valid stop bit. An invalid stop bit may result from noise on the serial lines or from simultaneous transmission by two CPUs. If a valid stop bit is not found, the Framing Error bit (FE) in SCON register (See Table 15.) bit is set. Software may examine FE bit after each reception to check for data errors. Once set, only software or a reset can clear FE bit. Subsequently received frames with valid stop bits cannot clear FE bit. When FE feature is enabled, RI rises on stop bit instead of the last data bit (See Figure 14. and Figure 15.). RXD D0 Start bit D1 D2 D3 D4 D5 D6 Data byte D7 Stop bit RI SMOD0=X FE SMOD0=1 Figure 14. UART Timings in Mode 1 Rev. F - 15 February, 2001 32 T89C51RD2 RXD D0 Start bit D1 D2 D3 D4 D5 D6 D7 Data byte D8 Ninth Stop bit bit RI SMOD0=0 RI SMOD0=1 FE SMOD0=1 Figure 15. UART Timings in Modes 2 and 3 6.6.2. Automatic Address Recognition The automatic address recognition feature is enabled when the multiprocessor communication feature is enabled (SM2 bit in SCON register is set). Implemented in hardware, automatic address recognition enhances the multiprocessor communication feature by allowing the serial port to examine the address of each incoming command frame. Only when the serial port recognizes its own address, the receiver sets RI bit in SCON register to generate an interrupt. This ensures that the CPU is not interrupted by command frames addressed to other devices. If desired, you may enable the automatic address recognition feature in mode 1. In this configuration, the stop bit takes the place of the ninth data bit. Bit RI is set only when the received command frame address matches the device's address and is terminated by a valid stop bit. To support automatic address recognition, a device is identified by a given address and a broadcast address. NOTE: The multiprocessor communication and automatic address recognition features cannot be enabled in mode 0 (i.e. setting SM2 bit in SCON register in mode 0 has no effect). 6.6.3. Given Address Each device has an individual address that is specified in SADDR register; the SADEN register is a mask byte that contains don't-care bits (defined by zeros) to form the device's given address. The don't-care bits provide the flexibility to address one or more slaves at a time. The following example illustrates how a given address is formed. To address a device by its individual address, the SADEN mask byte must be 1111 1111b. For example: SADDR SADEN Given 0101 0110b 1111 1100b 0101 01XXb The following is an example of how to use given addresses to address different slaves: Slave A: SADDR SADEN Given 1111 0001b 1111 1010b 1111 0X0Xb Slave B: SADDR SADEN Given 1111 0011b 1111 1001b 1111 0XX1b Slave C: SADDR SADEN Given 1111 0010b 1111 1101b 1111 00X1b 33 Rev. F - 15 February, 2001 T89C51RD2 The SADEN byte is selected so that each slave may be addressed separately. For slave A, bit 0 (the LSB) is a don't-care bit; for slaves B and C, bit 0 is a 1. To communicate with slave A only, the master must send an address where bit 0 is clear (e.g. 1111 0000b). For slave A, bit 1 is a 1; for slaves B and C, bit 1 is a don't care bit. To communicate with slaves B and C, but not slave A, the master must send an address with bits 0 and 1 both set (e.g. 1111 0011b). To communicate with slaves A, B and C, the master must send an address with bit 0 set, bit 1 clear, and bit 2 clear (e.g. 1111 0001b). 6.6.4. Broadcast Address A broadcast address is formed from the logical OR of the SADDR and SADEN registers with zeros defined as don't-care bits, e.g.: SADDR 0101 0110b SADEN 1111 1100b Broadcast =SADDR OR SADEN 1111 111Xb The use of don't-care bits provides flexibility in defining the broadcast address, however in most applications, a broadcast address is FFh. The following is an example of using broadcast addresses: Slave A: SADDR 1111 0001b SADEN 1111 1010b Broadcast 1111 1X11b, Slave B: SADDR 1111 0011b SADEN 1111 1001b Broadcast 1111 1X11B, Slave C: SADDR= 1111 0010b SADEN 1111 1101b Broadcast 1111 1111b For slaves A and B, bit 2 is a don't care bit; for slave C, bit 2 is set. To communicate with all of the slaves, the master must send an address FFh. To communicate with slaves A and B, but not slave C, the master can send and address FBh. 6.6.5. Reset Addresses On reset, the SADDR and SADEN registers are initialized to 00h, i.e. the given and broadcast addresses are XXXX XXXXb (all don't-care bits). This ensures that the serial port will reply to any address, and so, that it is backwards compatible with the 80C51 microcontrollers that do not support automatic address recognition. SADEN - Slave Address Mask Register (B9h) 7 6 5 4 3 2 1 0 4 3 2 1 0 Reset Value = 0000 0000b Not bit addressable SADDR - Slave Address Register (A9h) 7 6 5 Reset Value = 0000 0000b Not bit addressable Table 15. SCON Register Rev. F - 15 February, 2001 34 T89C51RD2 SCON - Serial Control Register (98h) 7 6 5 4 3 2 1 0 FE/SM0 SM1 SM2 REN TB8 RB8 TI RI Bit Number Bit Mnemonic 7 FE SM0 Description Framing Error bit (SMOD0=1) Clear to reset the error state, not cleared by a valid stop bit. Set by hardware when an invalid stop bit is detected. SMOD0 must be set to enable access to the FE bit Serial port Mode bit 0 Refer to SM1 for serial port mode selection. SMOD0 must be cleared to enable access to the SM0 bit Serial port Mode bit 1 SM0 SM1 Mode 0 0 1 1 0 1 0 1 0 1 2 3 Description Baud Rate Shift Register 8-bit UART 9-bit UART 9-bit UART FXTAL/12 (/6 in X2 mode) Variable FXTAL/64 or FXTAL/32 (/32 or 16 in X2 mode) Variable 6 SM1 5 SM2 4 REN Reception Enable bit Clear to disable serial reception. Set to enable serial reception. 3 TB8 Transmitter Bit 8 / Ninth bit to transmit in modes 2 and 3. Clear to transmit a logic 0 in the 9th bit. Set to transmit a logic 1 in the 9th bit. Serial port Mode 2 bit / Multiprocessor Communication Enable bit Clear to disable multiprocessor communication feature. Set to enable multiprocessor communication feature in mode 2 and 3, and eventually mode 1. This bit should be cleared in mode 0. Receiver Bit 8 / Ninth bit received in modes 2 and 3 Cleared by hardware if 9th bit received is a logic 0. Set by hardware if 9th bit received is a logic 1. In mode 1, if SM2 = 0, RB8 is the received stop bit. In mode 0 RB8 is not used. 2 RB8 1 TI Transmit Interrupt flag Clear to acknowledge interrupt. Set by hardware at the end of the 8th bit time in mode 0 or at the beginning of the stop bit in the other modes. 0 RI Receive Interrupt flag Clear to acknowledge interrupt. Set by hardware at the end of the 8th bit time in mode 0, see Figure 14. and Figure 15. in the other modes. Reset Value = 0000 0000b Bit addressable 35 Rev. F - 15 February, 2001 T89C51RD2 Table 16. PCON Register PCON - Power Control Register (87h) 7 6 5 4 3 2 1 0 SMOD1 SMOD0 - POF GF1 GF0 PD IDL Bit Number Bit Mnemonic 7 SMOD1 Serial port Mode bit 1 Set to select double baud rate in mode 1, 2 or 3. 6 SMOD0 Serial port Mode bit 0 Clear to select SM0 bit in SCON register. Set to to select FE bit in SCON register. 5 - 4 POF Power-Off Flag Clear to recognize next reset type. Set by hardware when VCC rises from 0 to its nominal voltage. Can also be set by software. 3 GF1 General purpose Flag Cleared by user for general purpose usage. Set by user for general purpose usage. 2 GF0 General purpose Flag Cleared by user for general purpose usage. Set by user for general purpose usage. 1 PD Power-Down mode bit Cleared by hardware when reset occurs. Set to enter power-down mode. 0 IDL Idle mode bit Clear by hardware when interrupt or reset occurs. Set to enter idle mode. Description Reserved The value read from this bit is indeterminate. Do not set this bit. Reset Value = 00X1 0000b Not bit addressable Power-off flag reset value will be 1 only after a power on (cold reset). A warm reset doesn't affect the value of this bit. Rev. F - 15 February, 2001 36 T89C51RD2 6.7. Interrupt System The T89C51RD2 has a total of 7 interrupt vectors: two external interrupts (INT0 and INT1), three timer interrupts (timers 0, 1 and 2), the serial port interrupt and the PCA global interrupt. These interrupts are shown in Figure 16. High priority interrupt IPH, IP 3 INT0 IE0 0 3 TF0 0 3 INT1 IE1 0 3 Interrupt polling sequence, decreasing from high to low priority TF1 0 3 PCA IT 0 RI TI 3 TF2 EXF2 3 0 0 Individual Enable Global Disable Low priority interrupt Figure 16. Interrupt Control System Each of the interrupt sources can be individually enabled or disabled by setting or clearing a bit in the Interrupt Enable register (See Table 18.). This register also contains a global disable bit, which must be cleared to disable all interrupts at once. Each interrupt source can also be individually programmed to one out of four priority levels by setting or clearing a bit in the Interrupt Priority register (See Table 19.) and in the Interrupt Priority High register (See Table 20.). shows the bit values and priority levels associated with each combination. The PCA interrupt vector is located at address 0033H. All other vectors addresses are the same as standard C52 devices. Rev. F - 15 February, 2001 37 T89C51RD2 Table 17. Priority Level Bit Values IPH.x IP.x Interrupt Level Priority 0 0 0 (Lowest) 0 1 1 1 0 2 1 1 3 (Highest) A low-priority interrupt can be interrupted by a high priority interrupt, but not by another low-priority interrupt. A high-priority interrupt can't be interrupted by any other interrupt source. If two interrupt requests of different priority levels are received simultaneously, the request of higher priority level is serviced. If interrupt requests of the same priority level are received simultaneously, an internal polling sequence determines which request is serviced. Thus within each priority level there is a second priority structure determined by the polling sequence. Table 18. IE Register IE - Interrupt Enable Register (A8h) 7 6 5 4 3 2 1 0 EA EC ET2 ES ET1 EX1 ET0 EX0 Bit Number Bit Mnemonic Description 7 EA Enable All interrupt bit Clear to disable all interrupts. Set to enable all interrupts. If EA=1, each interrupt source is individually enabled or disabled by setting or clearing its own interrupt enable bit. 6 EC PCA interrupt enable bit Clear to disable . Set to enable. 5 ET2 Timer 2 overflow interrupt Enable bit Clear to disable timer 2 overflow interrupt. Set to enable timer 2 overflow interrupt. 4 ES Serial port Enable bit Clear to disable serial port interrupt. Set to enable serial port interrupt. 3 ET1 Timer 1 overflow interrupt Enable bit Clear to disable timer 1 overflow interrupt. Set to enable timer 1 overflow interrupt. 2 EX1 External interrupt 1 Enable bit Clear to disable external interrupt 1. Set to enable external interrupt 1. 1 ET0 Timer 0 overflow interrupt Enable bit Clear to disable timer 0 overflow interrupt. Set to enable timer 0 overflow interrupt. 0 EX0 External interrupt 0 Enable bit Clear to disable external interrupt 0. Set to enable external interrupt 0. Reset Value = 0000 0000b Bit addressable 38 Rev. F - 15 February, 2001 T89C51RD2 Table 19. IP Register IP - Interrupt Priority Register (B8h) 7 6 5 4 3 2 1 0 - PPC PT2 PS PT1 PX1 PT0 PX0 Bit Number Bit Mnemonic 7 - 6 PPC PCA interrupt priority bit Refer to PPCH for priority level. 5 PT2 Timer 2 overflow interrupt Priority bit Refer to PT2H for priority level. 4 PS Serial port Priority bit Refer to PSH for priority level. 3 PT1 Timer 1 overflow interrupt Priority bit Refer to PT1H for priority level. 2 PX1 External interrupt 1 Priority bit Refer to PX1H for priority level. 1 PT0 Timer 0 overflow interrupt Priority bit Refer to PT0H for priority level. 0 PX0 External interrupt 0 Priority bit Refer to PX0H for priority level. Description Reserved The value read from this bit is indeterminate. Do not set this bit. Reset Value = X000 0000b Bit addressable Rev. F - 15 February, 2001 39 T89C51RD2 Table 20. IPH Register IPH - Interrupt Priority High Register (B7h) 7 6 5 4 3 2 1 0 - PPCH PT2H PSH PT1H PX1H PT0H PX0H Bit Number Bit Mnemonic 7 - 6 5 4 3 2 1 0 PPCH Description Reserved The value read from this bit is indeterminate. Do not set this bit. PCA interrupt priority bit high. PPCHPPC Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PT2H Timer 2 overflow interrupt Priority High bit PT2HPT2 Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PSH Serial port Priority High bit PSHPS Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PT1H Timer 1 overflow interrupt Priority High bit PT1HPT1 Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PX1H External interrupt 1 Priority High bit PX1HPX1 Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PT0H Timer 0 overflow interrupt Priority High bit PT0HPT0 Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PX0H External interrupt 0 Priority High bit PX0HPX0 Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest Reset Value = X000 0000b Not bit addressable 40 Rev. F - 15 February, 2001 T89C51RD2 6.8. Idle mode An instruction that sets PCON.0 causes that to be the last instruction executed before going into the Idle mode. In the Idle mode, the internal clock signal is gated off to the CPU, but not to the interrupt, Timer, and Serial Port functions. The CPU status is preserved in its entirely : the Stack Pointer, Program Counter, Program Status Word, Accumulator and all other registers maintain their data during Idle. The port pins hold the logical states they had at the time Idle was activated. ALE and PSEN hold at logic high levels. There are two ways to terminate the Idle. Activation of any enabled interrupt will cause PCON.0 to be cleared by hardware, terminating the Idle mode. The interrupt will be serviced, and following RETI the next instruction to be executed will be the one following the instruction that put the device into idle. The flag bits GF0 and GF1 can be used to give an indication if an interrupt occured during normal operation or during an Idle. For example, an instruction that activates Idle can also set one or both flag bits. When Idle is terminated by an interrupt, the interrupt service routine can examine the flag bits. The other way of terminating the Idle mode is with a hardware reset. Since the clock oscillator is still running, the hardware reset needs to be held active for only two machine cycles (24 oscillator periods) to complete the reset. 6.9. Power-Down Mode To save maximum power, a power-down mode can be invoked by software (refer to Table 13, PCON register). In power-down mode, the oscillator is stopped and the instruction that invoked power-down mode is the last instruction executed. The internal RAM and SFRs retain their value until the power-down mode is terminated. VCC can be lowered to save further power. Either a hardware reset or an external interrupt can cause an exit from power-down. To properly terminate power-down, the reset or external interrupt should not be executed before VCC is restored to its normal operating level and must be held active long enough for the oscillator to restart and stabilize. Only external interrupts INT0 and INT1 are useful to exit from power-down. For that, interrupt must be enabled and configured as level or edge sensitive interrupt input. Holding the pin low restarts the oscillator but bringing the pin high completes the exit as detailed in Figure 17.. When both interrupts are enabled, the oscillator restarts as soon as one of the two inputs is held low and power down exit will be completed when the first input will be released. In this case the higher priority interrupt service routine is executed. Once the interrupt is serviced, the next instruction to be executed after RETI will be the one following the instruction that put Lynx/Fox into power-down mode. INT0 INT1 XTAL1 Active phase Power-down phase Oscillator restart phase Active phase Figure 17. Power-Down Exit Waveform Exit from power-down by reset redefines all the SFRs, exit from power-down by external interrupt does no affect the SFRs. Exit from power-down by either reset or external interrupt does not affect the internal RAM content. NOTE: If idle mode is activated with power-down mode (IDL and PD bits set), the exit sequence is unchanged, when execution is vectored to interrupt, PD and IDL bits are cleared and idle mode is not entered. Rev. F - 15 February, 2001 41 T89C51RD2 This table shows the state of ports during idle and power-down modes. Mode Program Memory ALE PSEN PORT0 Idle Idle Power Down Power Down Internal External Internal External 1 1 0 0 1 1 0 0 Port Data* Floating Port Dat* Floating PORT1 PORT2 PORT3 Port Port Port Port Port Data Address Port Data Port Data Port Port Port Port Data Data Data Data Data Data Data Data * Port 0 can force a 0 level. A "one" will leave port floating. 42 Rev. F - 15 February, 2001 T89C51RD2 6.10. Hardware Watchdog Timer The WDT is intended as a recovery method in situations where the CPU may be subjected to software upset. The WDT consists of a 14-bit counter and the WatchDog Timer ReSeT (WDTRST) SFR. The WDT is by default disabled from exiting reset. To enable the WDT, user must write 01EH and 0E1H in sequence to the WDTRST, SFR location 0A6H. When WDT is enabled, it will increment every machine cycle while the oscillator is running and there is no way to disable the WDT except through reset (either hardware reset or WDT overflow reset). When WDT overflows, it will drive an output RESET HIGH pulse at the RST-pin. 6.10.1. Using the WDT To enable the WDT, user must write 01EH and 0E1H in sequence to the WDTRST, SFR location 0A6H. When WDT is enabled, the user needs to service it by writing to 01EH and 0E1H to WDTRST to avoid WDT overflow. The 14-bit counter overflows when it reaches 16383 (3FFFH) and this will reset the device. When WDT is enabled, it will increment every machine cycle while the oscillator is running. This means the user must reset the WDT at least every 16383 machine cycle. To reset the WDT the user must write 01EH and 0E1H to WDTRST. WDTRST is a write only register. The WDT counter cannot be read or written. When WDT overflows, it will generate an output RESET pulse at the RST-pin. The RESET pulse duration is 96 x TOSC , where TOSC = 1/FOSC . To make the best use of the WDT, it should be serviced in those sections of code that will periodically be executed within the time required to prevent a WDT reset. To have a more powerful WDT, a 27 counter has been added to extend the Time-out capability, ranking from 16ms to 2s @ FOSC = 12MHz. To manage this feature, refer to WDTPRG register description, Table 22. (SFR0A7h). Table 21. WDTRST Register WDTRST Address (0A6h) Reset value 7 6 5 4 3 2 1 X X X X X X X Write only, this SFR is used to reset/enable the WDT by writing 01EH then 0E1H in sequence. Rev. F - 15 February, 2001 43 T89C51RD2 Table 22. WDTPRG Register WDTPRG Address (0A7h) 7 6 5 4 3 2 1 0 T4 T3 T2 T1 T0 S2 S1 S0 Bit Number Bit Mnemonic 7 T4 6 T3 5 T2 4 T1 3 T0 2 S2 WDT Time-out select bit 2 1 S1 WDT Time-out select bit 1 0 S0 WDT Time-out select bit 0 Description Reserved The value read from this bit is undeterminated. Do not try to set this bit.. S2 0 0 0 0 1 1 1 1 S1S0 00 01 10 11 00 01 10 11 Selected Time-out (214 - 1) machine cycles, 16.3 ms @ 12 MHz (215 - 1) machine cycles, 32.7 ms @ 12 MHz (216 - 1) machine cycles, 65.5 ms @ 12 MHz (217 - 1) machine cycles, 131 ms @ 12 MHz (218 - 1) machine cycles, 262 ms @ 12 MHz (219 - 1) machine cycles, 542 ms @ 12 MHz (220 - 1) machine cycles, 1.05 s @ 12 MHz (221 - 1) machine cycles, 2.09 s @ 12 MHz Reset value XXXX X000 6.10.2. WDT during Power Down and Idle In Power Down mode the oscillator stops, which means the WDT also stops. While in Power Down mode the user does not need to service the WDT. There are 2 methods of exiting Power Down mode: by a hardware reset or via a level activated external interrupt which is enabled prior to entering Power Down mode. When Power Down is exited with hardware reset, servicing the WDT should occur as it normally should whenever the T89C51RD2 is reset. Exiting Power Down with an interrupt is significantly different. The interrupt is held low long enough for the oscillator to stabilize. When the interrupt is brought high, the interrupt is serviced. To prevent the WDT from resetting the device while the interrupt pin is held low, the WDT is not started until the interrupt is pulled high. It is suggested that the WDT be reset during the interrupt service routine. To ensure that the WDT does not overflow within a few states of exiting of powerdown, it is best to reset the WDT just before entering powerdown. In the Idle mode, the oscillator continues to run. To prevent the WDT from resetting the T89C51RD2 while in Idle mode, the user should always set up a timer that will periodically exit Idle, service the WDT, and re-enter Idle mode. If the WDT is activated, the power consumption in stand-by mode will be above the specified value. 44 Rev. F - 15 February, 2001 T89C51RD2 6.11. ONCE(TM) Mode (ON Chip Emulation) The ONCE mode facilitates testing and debugging of systems using T89C51RD2 without removing the circuit from the board. The ONCE mode is invoked by driving certain pins of the T89C51RD2; the following sequence must be exercised: * Pull ALE low while the device is in reset (RST high) and PSEN is high. * Hold ALE low as RST is deactivated. While the T89C51RD2 is in ONCE mode, an emulator or test CPU can be used to drive the circuit. Table 23. shows the status of the port pins during ONCE mode. Normal operation is restored when normal reset is applied. Table 23. External Pin Status during ONCE Mode ALE PSEN Port 0 Port 1 Port 2 Port 3 XTAL1/2 Weak pull-up Weak pull-up Float Weak pull-up Weak pull-up Weak pull-up Active (a) "Once" is a registered trademark of Intel Corporation. Rev. F - 15 February, 2001 45 T89C51RD2 6.12. Reduced EMI Mode The ALE signal is used to demultiplex address and data buses on port 0 when used with external program or data memory. Nevertheless, during internal code execution, ALE signal is still generated. In order to reduce EMI, ALE signal can be disabled by setting AO bit. The AO bit is located in AUXR register at bit location 0. As soon as AO is set, ALE is no longer output but remains active during MOVX and MOVC instructions and external fetches. During ALE disabling, ALE pin is weakly pulled high. Table 24. AUXR Register AUXR - Auxiliary Register (8Eh) 7 6 5 4 3 2 1 0 - - M0 - XRS1 XRS0 EXTRAM AO Bit Number Bit Mnemonic 7 - Reserved The value read from this bit is indeterminate. Do not set this bit. 6 - Reserved The value read from this bit is indeterminate. Do not set this bit. 5 M0 4 - 3 XRS1 XRS1 bit XRAM size: Accessible size of the XRAM. See Table 6. 2 XRS0 XRS0 bit XRAM size: Accessible size of the XRAM. Table 6. 1 EXTRAM 0 AO Description M0 bit: Pulse length in clock period Stretch MOVX control: the RD/ and the WR/ pulse length is increased according to the value of M0. see table 6 Reserved The value read from this bit is indeterminate. Do not set this bit. EXTRAM bit See Table 6. ALE Output bit Clear to restore ALE operation during internal fetches. Set to disable ALE operation during internal fetches. Reset Value = XX0X 1000b Not bit addressable Rev. F - 15 February, 2001 46 T89C51RD2 7. EEPROM data memory 7.1. General description The EEPROM memory block contains 2048 bytes and is organized in 32 pages (or rows) of 64 bytes. The necessary high programming voltage is generated on-chip using the standard Vcc pin of the microcontroller. The EEPROM memory block is located at the addresses 0000h to 07FFh of the XRAM memory space and is selected by setting control bits in the EECON register. A read in the EEPROM memory is done with a MOVX instruction. A physical write in the EEPROM memory is done in two steps : write data in the column latches and transfer of all data latches in a EEPROM memory row (programming). The number of data written in the page may vary from 1 to 64 (the page size). When programming, only the data written in the column latch are programmed. This provides the capability to program the whole memory by bytes, by page or by a number of bytes in a page. 7.2. Write Data in the column latches Data is written by byte to the column latches as if it was in an external RAM memory. Out of the 16 address bits of the data pointer, the 10 MSB are used for page selection and 6 are used for byte selection. Between two EEPROM programming, all addresses in the column latches must remain in the same page, thus the 10MSB must be unchanged. The following procedure is used to write in the colums latches : * * * * * Map the program space (Set bit EEE of EECON register) Load DPTR with the address to write Load A register with the data to be written Execute a MOVX @DPTR, A If needed loop the three last instructions until the end of a 64bytes page 7.3. Programming The EEPROM programming consists on the following actions : * write one or more bytes in a page in the column latches. Normally, all bytes must belong to the same page; if this is not the case, the first page address is latched and the others are discarded. * Set EETIM with the value corresponding to the XTAL frequency. * Launch the programming by writing the control sequence (52h or 50h followed by A2h or A0h) to the EECON register (see Table 25). * EEBUSY flag in EECON is then set by hardware to indicate that programming is in progress and that EEPROM segment is not available for read. * The end of programming is signaled by a hardware clear of the EEBUSY flag. Rev. F - 15 February, 2001 47 T89C51RD2 Example : ..... Wait : MOV ANL JNZ MOV MOV MOVX MOV MOV .... ; DPTR = EEPROM data pointer, A = Data to write A,EECON A,#01h Wait EETIM,#3Ch ; 12MHz*5 = 3Ch EECON,#02h ; EEE=1 EEPROM mapped @DPTR,A ; Write data to EEPROM EECON,#50h or 52h ; Write Sequence EECON,#A0h or A2h 7.4. Read Data The following procedure is used to read the data store in the EEPROM memory: * Map the program space (Set bit EEE of EECON register) * Load DPTR with the address to read * Execute a MOVX A, @DPTR Example : ... MOV EECON,#02h MOVX A,@DPTR ... ; DPTR = EEPROM data pointer ; EEE=1 EEPROM mapped ; Read data from EEPROM ; A = Data 7.5. Registers Table 25. EECON Register EECON (S:0D2h) EEPROM Control Register 7 6 5 4 3 2 1 0 EEPL3 EEPL2 EEPL1 EEPL0 - - EEE EEBUSY Bit Number Bit Mnemonic 7-4 EEPL3-0 3 - Not implemented, reserved for future use.a 2 - Not implemented, reserved for future use.b 1 0 a. b. EEE EEBUSY Description Programming Launch command bits Write 5Xh followed by AXh to EECON to launch the programming. Enable EEPROM Space bit Set to map the EEPROM space during MOVX instructions (Write in the column latches) Clear to map the data space during MOVX. Programming Busy flag Set by hardware when programming is in progress. Cleared by hardware when programming is done. Can not be set or cleared by software. User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features. In that case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate. User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features. In that case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate. Reset Value= XXXX XX00b 48 Rev. F - 15 February, 2001 T89C51RD2 Table 26. EETIM Register EETIM (S:0D3h) EEPROM timing Control Register 7 6 5 4 3 2 1 0 EETIM Bit Number 7-0 Bit Mnemonic EETIM Description Write Timer Register The write timer register value is required to adapt the write time to the oscillator frequency Value = 5 * Fxtal (MHz) in normal mode, 10 * Fxtal in X2 mode. Example : Fxtal = 33 MHZ, EETIM = 0A5h Reset Value= 0000 0000b Rev. F - 15 February, 2001 49 T89C51RD2 8. FLASH EEprom Memory 8.1. General description The FLASH memory increases EPROM and ROM functionality with in-circuit electrical erasure and programming. It contains 64K bytes of program memory organized in 512 pages of 128 bytes. This memory is both parallel and serial In-System Programmable (ISP). ISP allows devices to alter their own program memory in the actual end product under software control. A default serial loader (bootloader) program allows ISP of the FLASH. The programming does not require 12v external programming voltage. The necessary high programming voltage is generated on-chip using the standard VCC pins of the microcontroller. 8.2. Features * FLASH E2PROM internal program memory. * The last 1K bytes of the FLASH is used to store the low-level in-system programming routines and a default serial loader. If the application does not need to use the ISP and does not expect to modify the FLASH content, the Boot FLASH sector can be erased to provide access to the full 64K byte FLASH memory. * Boot vector allows user provided FLASH loader code to reside anywhere in the FLASH memory space. This configuration provides flexibility to the user. * * * * Default loader in Boot FLASH allows programming via the serial port without the need of a user provided loader. Up to 64K byte external program memory if the internal program memory is disabled (EA = 0). Programming and erase voltage with standard 5V or 3V VCC supply. Read/Programming/Erase: * Byte-wise read (without wait state). * Byte or page erase and programming (10 ms). * Typical programming time (63K bytes) in 20 s. Parallel programming with 87C51 compatible hardware interface to programmer. * * Programmable security for the code in the FLASH. * 100k write cycles * 10 years data retention 8.3. FLASH Programming and Erasure The 64K bytes FLASH is programmed by bytes or by pages of 128 bytes. It is not necessary to erase a byte or a page before programming. The programming of a byte or a page includes a self erase before programming. There are three methods to program the FLASH memory: * First, the on-chip ISP bootloader may be invoked which will use low level routines to program the pages. The interface used for serial downloading of FLASH is the UART. * Second, the FLASH may be programmed or erased in the end-user application by calling low-level routines through a common entry point in the Boot loader. * Third, the FLASH may be programmed using the parallel method by using a conventional EPROM programmer. The parallel programming method used by these devices is similar to that used by EPROM 87C51 but it is not identical and the commercially available programmers need to have support for the T89C51RD2. Rev. F - 15 February, 2001 50 T89C51RD2 The bootloader and the In Application Programming (IAP) routines are located in the last kilobyte of the FLASH, leaving 63k bytes available for the application with ISP. 8.4. FLASH registers and memory map The T89C51RD2 FLASH memory uses several registers for his management: * Flash control register is used to select the Flash memory spaces and launch the Flash programming sequence. * Hardware registers can only be accessed through the parallel programming modes which are handled by the parallel programmer. * Software registers are in a special page of the FLASH memory which can be accessed through the API or with the parallel programming modes. This page, called "Extra FLASH Memory", is not in the internal FLASH program memory addressing space. 8.4.1. FLASH register FCON (S:D1h) FLASH control register 7 6 5 4 3 2 1 0 FPL3 FPL2 FPL1 FPL0 FPS FMOD1 FMOD0 FBUSY Bit Number Bit Mnemonic 7-4 3 2-1 0 FPL3:0 FPS FMOD1:0 FBUSY Description Programming Launch command bits Write 5h followed by Ah to launch the programming. FLASH Map Program Space Clear to map the data space during MOVX Set to map the FLASH space during MOVX (write) or MOVC (read) instructions (Write in the column latches) FLASH Mode Select the addressed space 00: User (0000h-FFFFh) 01: XAF 10: Hardware byte 11: reserved FLASH Busy Set by hardware when programming is in progress. Clear by hardware when programming is done. Can not be cleared by software Reset Value = xxxx 0000b Figure 18. FCON register The Flash programming application note and API source code are available on request. 8.4.2. Hardware register The only hardware register of the T89C51RD2 is called Hardware Security Byte (HSB). After full FLASH erasure, the content of this byte is FFh; each bit is active at low level. 51 Rev. F - 15 February, 2001 T89C51RD2 Table 27. Hardware Security Byte (HSB) 7 6 5 4 3 2 1 0 SB BLJB BLLB - - LB2 LB1 LB0 Bit Number Bit Mnemonic 7 SB Description Safe Bit This bit must be cleared to secure the content of the HSB. Only security level can be increased. 6 BLJB Boot loader Jump Bit Set to force hardware boot address at 0000h. (unless previously force by hardware conditions as described in the chapter 9.6). Clear to force hardware boot address at FC03h (default). 5 BLLB Boot loader Lock Bit Set to allow programming and writing of the boot loader segment. Clear to forbid software programming and writing of the boot loader segment (default). This protection protect only ISP or IAP access; protection through parallel access is done globally by the lock bits LB2-0. 4 - Reserved Do not clear this bit. 3 - Reserved Do not clear this bit. 2-0 LB2-0 User Memory Lock Bits See Table 29 8.4.2.1. Boot Loader Lock Bit (BLLB) One bit of the HSB is used to secure by hardware the internal boot loader sector against software reprogramming. When the BLLB is cleared, any attempt to write in the boot loader segment (Address FC00h to FFFFh) will have no effect. This protection applies for software writing only. Boot Loader Jump Bit (BLJB) One bit of the HSB, the BLJB bit, is used to force the boot address: * When this bit is set the boot address is 0000h. * When this bit is reset the boot address is FC03h. By default, this bit is cleared and the ISP is enabled. 8.4.2.2. FLASH memory lock bits The three lock bits provide different levels of protection for the on-chip code and data, when programmed according to Table 29. Rev. F - 15 February, 2001 52 T89C51RD2 Table 28. Program Lock bits Protection description Program Lock Bits Security level LB0 LB1 LB2 1 U U U No program lock features enabled. MOVC instruction executed from external program memory returns non encrypted data. 2 P U U MOVC instruction executed from external program memory are disabled from fetching code bytes from internal memory, EA is sampled and latched on reset, and further parallel programming of the FLASH is disabled.ISP and software programming with API are still allowed. 3 X P U Same as 2, also verify through parallel programming interface is disabled. 4 X X P Same as 3, also external execution is disabled. U: unprogrammed or "one" level. P: programmed or "zero" level. X:do not care WARNING: Security level 2 and 3 should only be programmed after FLASH and code verification. These security bits protect the code access through the parallel programming interface. They are set by default to level 4. The code access through the ISP is still possible and is controlled by the "software security bits" which are stored in the extra FLASH memory accessed by the ISP firmware. To load a new application with the parallel programmer, a chip erase must first be done. This will set the HSB in its inactive state and will erase the FLASH memory, including the boot loader and the "Extra FLASH Memory" (XAF). If needed, the 1K boot loader and the XAF content must be programmed in the FLASH; the code is provided by ATMEL Wireless and Microcontrollers (see section 8.7. ); the part reference can always be read using FLASH parallel programming modes. 8.4.2.3. Default values The default value of the HSB provides parts ready to be programmed with ISP: * * * * SB: Cleared to secure the content of the HSB. BLJB: Cleared to force ISP operation. BLLB: Clear to protect the default boot loader. LB2-0: Security level four to protect the code from a parallel access with maximum security. 8.4.3. Software registers Several registers are used, in factory and by parallel programmers, to make copies of hardware registers contents. These values are used by ATMEL Wireless and Microcontrollers ISP (see section 8.7. ). These registers are in the "Extra FLASH Memory" part of the FLASH memory. This block is also called "XAF" or eXtra Array FLASH. They are accessed in the following ways: * Commands issued by the parallel memory programmer. * Commands issued by the ISP software. * Calls of API issued by the application software. 53 Rev. F - 15 February, 2001 T89C51RD2 They are several software registers described in Table 29 Table 29. Default values Mnemonic Default value BSB Boot Status Byte FFh SBV Software Boot Vector FCh HSB Copy of the Hardware security byte 18h or 1Bh SSB Software Security Byte FFh Copy of the Manufacturer Code ATMEL Wireless and Microcontrollers 58h Copy of the Device ID #1: Family Code D7h C51 X2, Electrically Erasable Copy of the Device ID #2: memories size and type T89C51RD2 memories size FCh T89C51RD2, Copy of the Device ID # 3: name and revi- FFh revision 0 sion After programming the part by ISP, the BSB must be reset (00h) in order to allow the application to boot at 0000h. The content of the Software Security Byte (SSB) is described in Table 30 and Table 31 To assure code protection from a parallel access, the HSB must also be at the required level. Table 30. Software Security Byte (SSB) 7 6 5 4 3 2 1 0 - - - LB1 - - - LB0 Bit Number Bit Mnemonic 7 - Reserved Do not clear this bit. 6 - Reserved Do not clear this bit. 5 - Reserved Do not clear this bit. 4 LB1 User Memory Lock Bit See Table 31 1-3 - Reserved Do not clear this bit. 0 LB0 User Memory Lock Bit See Table 31 Description The three lock bits provide different levels of protection for the on-chip code and data, when programmed according to Table 31. Rev. F - 15 February, 2001 54 T89C51RD2 Table 31. Program Lock bits of the SSB Protection description Program Lock Bits Security level LB0 LB1 1 U U No program lock features enabled. U following commands are disabled: - program byte - program status byte and boot vector - erase status byte and boot vector P Same as 2 and following commands also disabled: - read byte - read status byte and boot vector - blank check - program SSB level2 2 3 P X U: unprogrammed or "one" level. P: programmed or "zero" level. X:do not care WARNING: Security level 2 and 3 should only be programmed after FLASH and code verification. 8.5. FLASH memory status T89C51RD2 parts are delivered in standard with the ISP boot in the FLASH memory. After ISP or parallel programming, the possible contents of the FLASH memory are summarized on the figure below: Figure 19. FLASH memory possible contents FC00h Boot Virgin Boot Application Boot Virgin or appli Boot Application Dedicated ISP Virgin or appli Boot Virgin or appli Dedicated ISP 0000h Default After ISP After ISP After parallel programming After parallel programming After parallel programming 8.6. Boot process Boot loader FLASH When the user application programs its own FLASH memory, all of the low level details are handled by a code that is permanently contained in a 1k byte "Boot FLASH" and is located in the last kilobyte of the FLASH memory from FC00h to FFFFh (See Figure 20). A user program simply calls the common entry point in the Boot FLASH with appropriate parameters to accomplish the desired operation. Boot FLASH operations include functions like: 55 Rev. F - 15 February, 2001 T89C51RD2 erase block, program byte or page, verify byte or page, program security lock bit, etc. The Boot FLASH can be locked to prevent erasing. If erased, the Boot FLASH can be restored by parallel programming. Indeed, ATMEL Wireless and Microcontrollers provides the binary code of the default FLASH boot loader (see section 8.7. ). FFF0 Entry point for API FC03 Status byte check FC00 ISP start Figure 20. Boot loader memory map Reset Code Execution At the falling edge of reset (unless the hardware conditions on PSEN, EA and ALE are set as described below), the T89C51RD2 reads the BLJB bit in the HSB byte. If this bit is set, it jumps to 0000h and if not, it jumps to FC03h. At this address, the boot software reads two special FLASH registers: the Software Boot Vector (SBV) and the Boot Status Byte (BSB). If the BSB is set to zero, power-up execution starts at location 0000h, which is the normal start address of the user's application code. When the Status Byte is set to a value other than zero, the contents of the Boot Vector is used as the high byte of the execution address and the low byte is set to 00h. The factory default setting is FCh, corresponding to the address FC00h for the factory default FLASH ISP boot loader. A custom boot loader can be written with the Boot Vector set to the custom boot loader address. It is recommanded to set the BSB before any other IAP so the device automatically resumes ISP when reset. ISP routines shall only clear BSB after succesfull IAP completion. Hardware Activation of the Boot Loader The default boot loader can also be executed by holding PSEN LOW, EA HIGH, and ALE HIGH (or not connected) at the falling edge of RESET. This has the same effect as having a non-zero status byte anf the Boot Vector equal to FCh. This allows an application to be built that will normally execute the end user's code but can be manually forced into default ISP operation. As PSEN has the same structure as P1-P3, the current to force PSEN to 0 as ITL is defined in the DC parameters. If the factory default setting for the Boot Vector (FCh) is changed, it will no longer point to the ISP default FLASH boot loader code. It can be restored: * With the default ISP activated with hardware conditions on PSEN, EA and ALE. * With a customized loader (in the end user application) that provides features for erasing and reprogramming of the Boot Vector and BSB. * Through the parallel programming method. After programming the FLASH, the status byte should be programmed to zero in order to allow execution of the user's application code beginning at address 0000h. Rev. F - 15 February, 2001 56 T89C51RD2 Boot process summary The boot process is summarized on the following flowchart: Reset Falling Edge Yes (PSEN =0, EA =1, and ALE =1 or not connected) Hardware Conditions ? No Yes BLJB = 1 ? Hardware No Jump to FC03h Software BSB= 0 BSB ? Jump to 0000h BSB 00h USER APPLICATION Software Boot Vector ? SBV= FCh Jump to FC00h SBV FCh = XXh DEFAULT BOOT LOADER Jump to XX00h CUSTOM BOOT LOADER - BSB: Boot Status Byte - BLJB: Boot Loader Jump Bit (Hardware Bit set to 0 by default) Figure 21. Boot process flowchart 57 Rev. F - 15 February, 2001 T89C51RD2 8.7. In-System Programming (ISP) The In-System Programming (ISP) is performed without removing the microcontroller from the system. The InSystem Programming (ISP) facility consists of a series of internal hardware resources coupled with internal firmware to facilitate remote programming of the T89C51RD2 through the serial port. This firmware is embedded within each T89C51RD2 device going out of factory. The ATMEL Wireless and Microcontrollers In-System Programming (ISP) facility has made in-circuit programming in an embedded application possible with a minimum of additional expense in components and circuit board area. The ISP function uses four pins: TxD, RxD, VSS , VCC. Only a small connector needs to be available to interface the application to an external circuit in order to use this feature. Application schematic can found be in the demonstration and ISP board user manual. Using the In-System Programming (ISP) The ISP feature allows a wide range of baud rates in the user application. It is also adaptable to a wide range of oscillator frequencies. This is accomplished by measuring the bit-time of a single bit in a received character. This information is then used to program the baud rate in terms of timer counts based on the oscillator frequency. The ISP feature requires that an initial character (an uppercase U) be sent to the T89C51RD2 to establish the baud rate. The ISP firmware provides auto-echo of received characters. Once baud rate initialization has been performed, the ISP firmware will only accept Intel Hex-type records. Intel Hex records consist of ASCII characters used to represent hexadecimal values and are summarized below: :NNAAAARRDD..DDCC<crlf> In the Intel Hex record, the "NN" represents the number of data bytes in the record. The T89C51RD2 will accept up to 16 (10h) data bytes. The "AAAA" string represents the address of the first byte in the record. If there are zero bytes in the record, this field is often set to ``0000''. The "RR" string indicates the record type. A record type of "00" is a data record. A record type of "01" indicates the end-of-file mark. In this application, additional record types will be added to indicate either commands or data for the ISP facility. The "DD" string represents the data bytes. The maximum number of data bytes in a record is limited to 16 (decimal). The "CC" string represents the checksum byte. ISP commands are summarized in Table 32. As a record is received by the T89C51RD2, the information in the record is stored internally and a checksum calculation is performed and compared to ``CC''. The operation indicated by the record type is not performed until the entire record has been received. Should an error occur in the checksum, the T89C51RD2 will send an "X" out the serial port indicating a checksum error. If the checksum calculation is found to match the checksum in the record, then the command will be executed. In most cases, successful reception of the record will be indicated by transmitting a "." character out the serial port (displaying the contents of the internal program memory is an exception). In the case of a Data Record (record type ``00''), an additional check is made. A "." character will NOT be sent unless the record checksum matched the calculated checksum and all of the bytes in the record were successfully programmed. For a data record, an "X" indicates that the checksum failed to match, and an "R" character indicates that one of the bytes did not properly program. ATMEL Wireless and Microcontrollers_ISP, a software utility to implement ISP programming with a PC, is available from ATMEL Wireless and Microcontrollers. Please visit our web site http://www.atmel-wm.com. Rev. F - 15 February, 2001 58 T89C51RD2 Table 32. Intel-Hex Records Used by In-System Programming RECORD TYPE COMMAND/DATA FUNCTION 00 Data Record :nnaaaa00dd....ddcc Where: Nn = number of bytes (hex) in record aaaa = memory address of first byte in record dd....dd = data bytes cc = checksum Example: :05008000AF5F67F060B6 (program address 80h to 85h with data AF ... 60) 01 End of File (EOF), no operation :xxxxxx01cc Where: xxxxxx = required field, but value is a "don't care" cc = checksum Example: :00000001FF 02 Specify Oscillator Frequency (Not required, left for Philips compatibility) :01xxxx02ddcc Where: xxxx = required field, but value is a "don't care" dd = required field, but value is a "don't care" cc = checksum Example: :0100000210ED 59 Rev. F - 15 February, 2001 T89C51RD2 Table 32. Intel-Hex Records Used by In-System Programming Miscellaneous Write Functions :nnxxxx03ffssddcc Where: nn = number of bytes (hex) in record xxxx = required field, but value is a "don't care" 03 = Write Function ff = subfunction code ss = selection code dd = data input (as needed) cc = checksum Subfunction Code = 04 (Reset Boot Vector and Status Byte) ff = 04 ss = don't care dd = don't care Example: :020000030400F8 Reset boot vector (FCh) and status byte (FFh) 03 Subfunction Code = 05 (Program Software Security Bits) ff = 05 ss = 00 program software security bit 1 (Level 2 inhibit writing to FLASH) ss = 01 program software security bit 2 (Level 3 inhibit FLASH verify) ss = 02 program security bit 3 (No effect, left for Philips compatibity; disable external memory is already set in the default hardware security byte) Example: :020000030501F6 program security bit 2 Subfunction Code = 06 (Program Status Byte or Boot Vector) ff = 06 ss = 00 program BSB ss = 01 program boot vector Example: :03000003060100F5 program boot vector with 00 Subfunction Code = 07 (Full chip erase) ff = 07 Example: :0100000307F5 full chip erase (include boot vector / status byte and software security bit erase) 04 Display Device Data or Blank Check Record type 04 causes the contents of the entire FLASH array to be sent out the serial port in a formatted display. This display consists of an address and the contents of 16 bytes starting with that address. No display of the device contents will occur if security bit 2 has been programmed. The dumping of the device data to the serial port is terminated by the reception of any character. General Format of Function 04 :05xxxx04sssseeeeffcc Where: 05 = number of bytes (hex) in record xxxx = required field, but value is a "don't care" 04 = "Display Device Data or Blank Check" function code ssss = starting address eeee = ending address ff = subfunction 00 = display data 01 = blank check cc = checksum Example: :0500000440004FFF0069 (display 4000-4FFF) Rev. F - 15 February, 2001 60 T89C51RD2 Table 32. Intel-Hex Records Used by In-System Programming Miscellaneous Read Functions General Format of Function 05 :02xxxx05ffsscc Where: 02 = number of bytes (hex) in record xxxx = required field, but value is a "don't care" 05= "Miscellaneous Read" function code ffss = subfunction and selection code 0000 = read copy of the signature byte - manufacturer id (58H) 0001 = read copy of the signature byte - device ID# 1 (Family code) 0002 = read copy of the signature byte - device ID # 2 (Memories size and type) 0003 = read copy of the signature byte - device ID # 3 (Product name and revision) 0700 = read the software security bits 0701 = read status byte (BSB) 0702 = read Boot Vector (SBV) 0703 = read copy of the HSB 0800 = read bootloader version cc = checksum Example: :020000050001F0 read copy of the signature byte - device id # 1 05 8.8. In-Application Programming Method Several Application Program Interface (API) calls are available for use by an application program to permit selective erasing and programming of FLASH pages. All calls are made through a common interface, PGM_MTP. The programming functions are selected by setting up the microcontroller's registers before making a call to PGM_MTP at FFF0h. Results are returned in the registers. The API calls are shown in Table 33. A set of Philips compatible API calls is provided. When several bytes have to be programmed, it is highly recommanded to use the ATMEL Wireless and Microcontrollers API "PROGRAM DATA PAGE" call. Indeed, this API call writes up to 128 bytes in a single command. Table 33. API calls API call PROGRAM DATA BYTE 61 Parameter Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 02h DPTR = address of byte to program ACC = byte to program Return Parameter ACC = 00 if pass, !00 if fail Rev. F - 15 February, 2001 T89C51RD2 Table 33. API calls PROGRAM DATA PAGE Input Parameters: R0 = osc freq (integer Not required) R1 = 09h DPTR0 = address of the first byte to program in the FLASH memory DPTR1 = address in XRAM of the first data to program (second data pointer) ACC = number of bytes to program Return Parameter ACC = 00 if pass, !00 if fail Remark: number of bytes to program is limited such as the FLASH write remains in a single 128bytes page. Hence, when ACC is 128, valid values of DPL are 00h, or, 80h. ERASE BOOT VECTOR STATUS BYTE Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 04h DPH = 00h DPL = don't care Return Parameter none PROGRAM SOFTWARE SECURITY BIT Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 05h DPH = 00h DPL = 00h - security bit # 1 (inhibit writing to FLASH) 01h - security bit # 2 (inhibit FLASH verify) 10h - allows ISP writing to FLASH* 11h - allows ISP FLASH verify* Return Parameter none PROGRAM BOOT STATUS BYTE Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 06h DPH = 00h DPL = 00h - program status byte ACC = status byte Return Parameter ACC = status byte PROGRAM BOOT VECTOR READ DEVICE DATA READ copy of the MANUFACTURER ID Rev. F - 15 February, 2001 Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 06h DPH = 00h DPL = 01h - program boot vector ACC = boot vector Return Parameter ACC = boot vector Input Parameters: R1 = 03h DPTR = address of byte to read Return Parameter ACC = value of byte read Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 00h DPH = 00h DPL = 00h (manufacturer ID) Return Parameter ACC = value of byte read 62 T89C51RD2 Table 33. API calls API call Parameter READ copy of the device ID # 1 Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 00h DPH = 00h DPL = 01h (device ID # 1) Return Parameter ACC = value of byte read READ copy of the device ID # 2 Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 00h DPH = 00h DPL = 02h (device ID # 2) Return Parameter ACC = value of byte read READ copy of the device ID # 3 Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 00h DPH = 00h DPL = 03h (device ID # 2) Return Parameter ACC = value of byte read READ SOFTWARE SECURITY BITS Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 07h DPH = 00h DPL = 00h (Software security bits) Return Parameter ACC = value of byte read READ copy of the HARDWARE SECURITY BITS Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 07h DPH = 00h DPL = 03h (Hardtware security bits) Return Parameter ACC = value of byte read READ BOOT VECTOR Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 07h DPH = 00h DPL = 02h (boot vector) Return Parameter ACC = value of byte read READ BOOTLOADER VERSION Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 08h Return Parameter ACC = value of byte read READ BOOT STATUS BYTE Input Parameters: R0 = osc freq (integer Not required, left for Philips compatibility) R1 = 07h DPH = 00h DPL = 01h (status byte) Return Parameter ACC = value of byte read 63 Rev. F - 15 February, 2001 T89C51RD2 Note: These functions can only be called by user's code. The standard boot loader cannot decrease the security level. 8.9. FLASH Parallel Programming 8.9.1. Signature bytes Four hardware read only registers have to be accessed with parallel static test modes (mode TMS) in order to control the FLASH parallel programmimg: * * * * Manufacturer code Device ID # 1: Family code Device ID # 2: Memories size and type Device ID # 3: Name and revision As these registers can only be accessed by hardware, they must be read by the parallel programmers and then copied in the XAF in order to make their values accessible by software (ISP or API). 8.9.2. Set-up modes In order to program and verify the FLASH or to read the signature bytes, the T89C51RD2 is placed in specific set-up modes (See Figure 22). Control and program signals must be held at the levels indicated in Table 37. and Table 38.(Please notice that each mode is defined over the two tables Rev. F - 15 February, 2001 64 T89C51RD2 Mode Name Mode Rst Psen PELCK Program or Erase Lock. Disable the Erasure or Programming access 1 0 PEULCK Program or Erase UnLock. Enable the Erasure or Programming access 1 0 EA P2.6 P2.7 P3.6 P3.7 P0[7..0] __ |_| 1 1 0 1 0 xx Note3 1 1 0 1 0 55-AA 1 0 1 1 1 xx __ |_| Write Code Data (byte) or write Page Always precedeed by PGML 1 PGML Memory Page Load (up to 128 bytes) 1 0 Note2 1 0 1 0 1 Din PGMV Read Code Data (byte) 1 0 1 1 0 __ |_| 1 1 Dout VSB Read Security Byte (=HSB) 1 0 1 1 0 __ |_| 0 1 Dout PGMS Write Security Byte (Note 4) (security byte = HSB) 1 0 10ms 1 1 1 0 0 Din CERR Chip Erase User + XAF 1 0 10ms 1 1 0 0 0 xx 1 1 1 0 1 xx 1 1 1 0 1 Din 0 0 Dout = 58h D7h FCh FFh 0 0 Dout PGMC 0 Internally timed __ |_| PGXC Write Byte or Page in Extra Memory (XAF) Always precedeed by PGXL 1 0 PGXL Memory Page Load XAF (up to 128 bytes) 1 0 TMS Read Signature bytes 30h (Manufacturer code) 31h (Device ID #1) 60h (Device ID #2) 61h (Device ID #3) 1 0 1 1 0 __ |_| Read Extra Memory (XAF) 1 0 1 1 0 __ |_| RXAF 65 Ale __ |_| Internally timed Note2 Rev. F - 15 February, 2001 T89C51RD2 Mode Name Mode P1[7..0] P2[5..0] P3.0 P3.1 P3.2 P3.3 P3.4 P3.5 PELCK Program or Erase Lock. Disable the Erasure or Programming access xx xx x x x 1 x x PEULCK Program or Erase UnLock. Enable the Erasure or Programming access xx xx x x x 0 x x PGMC Write Code Data (byte) or write Page Always precedeed by PGML A7-A0 A13-A8 1 x Note1 0 A14 A15 PGML Memory Page Load (up to 128 bytes) A7-A0 A13-A8 1 x x 0 A14 A15 PGMV Read Code Data (byte) A7-A0 A13-A8 1 x x 1 A14 A15 Read Security Byte (=HSB) xx xx 1 x x 1 x x PGMS Write lock Byte (Note 4) (security byte = HSB) xx xx 1 x Note1 0 x x CERR Chip Erase User + XAF xx xx 1 x x 0 x x PGXC Write Byte or Page Extra Memory (XAF) Always precedeed by PGXL A7-A0 (0-7F) xx 1 x Note1 0 x x PGXL Memory Page Load XAF (up to 128 bytes) A7-A0 (0-7F) xx 1 x x 1 x x TMS Read Signature bytes 30h (Manufacturer code) 31h (Device ID #1) 60h (Device ID #2) 61h (Device ID #3) 30h 31h 60h 61h x x x x 1 x x Addr (0-7F) 00 1 x x 0 x x VSB RXAF Read Extra Memory (XAF) Note 1: P3.2 is pulled low during programming to indicate RDY/BUSY. (P3.2 = 1 Ready; P3.2 = 0 Busy). Note 2: In Page Load Mode the current byte is loaded on ALE rising edge. Note 3: After a power up all external test mode to program or to erase the FLASH are locked to avoid any untimely programming or erasure. After each programming or erasure test mode, it's advised to lock this feature (test mode PELCK). To validate the test mode mode PEULCK the following sequence has to be applied: Test Mode PEULCK with ALE = 1. Pulse on ALE (min width=25clk) with P0=55 (P0 latched on ALE rising edge) Pulse on ALE (min width=25clk) with P0=AA (P0 latched on ALE rising edge) Note 4: The highest security bit (bit 7) is used to secure the 7 lowest bit erasure. The only way to erase this bit is to erase the whole FLASH memory. Procedure to program security bits (After array programming): - program bit7 to 0, program all other bits ( 1 = erased, 0 = programmed). - test mode PGMS (din = HSB). Procedure to erase security byte: - test mode CERR: erase all array included HSB. - program hardware security byte to FF: test mode PGMS (din = FF). 8.9.3. Definition of terms Address Lines:P1.0-P1.7, P2.0-P2.5, P3.4-P3.5, respectively for A0-A15. Data Lines:P0.0-P0.7 for D0-D7 Control Signals:RST, PSEN, P2.6, P2.7, P3.2, P3.3, P3.6, P3.7. Program Signals: ALE/PROG, EA Rev. F - 15 February, 2001 66 T89C51RD2 +5V EA PROGRAM SIGNALS* VCC ALE/PROG RST PSEN P2.6 P2.7 P3.3 P3.6 P3.7 CONTROL SIGNALS* 4 to 6 MHz P0.0-P0.7 D0-D7 P1.0-P1.7 A0-A7 XTAL1 P2.0-P2.5 A8-A13 P3.4 A14 P3.5 A15 VSS GND Figure 22. Set-Up Modes Configuration 8.9.4. Programming Algorithm To program the T89C51RD2 the following sequence must be exercised: * Check the signature bytes * Check the HSB (VSB mode) If the security bits are activated, the following commands must be done before programming: * * * * * * Unlock test modes (PEULCK mode, pulse 55h and AAh) Chip erase (CERR mode) Write FFh in the HSB (PGMS mode) Write the signature bytes content in the XAF As the boot loader and the XAF content is lost after a "chip erase", it must be reprogrammed if needed. Disable programming access (PELCK mode) To write a page in the FLASH memory, execute the following steps: * Step 0: Enable programming access (PEULCK mode) * Step 1: Activate the combination of control signals (PGML mode) * Step 2: Input the valid address on the address lines (High order bits of the address must be stable during the complete ALE low time) * Step 3: Activate the combination of control signals (PGML mode) * Step 4: Input the appropriate data on the data lines. * Step 5: Pulse ALE/PROG once. Repeat step 2 through 5 changing the address and data for end of a 128 bytes page * Step 6: Enable programming access (PEULCK mode) * Step 7: Activate the combination of control signals (PGMC mode) 67 Rev. F - 15 February, 2001 T89C51RD2 * Step 8: Input the valid address on the address lines. * Step 9: Pulse ALE/PROG once until P3.2 is high or the specified write time is reached. Repeat step 0 through 9 changing the address and data until the entire array or until the end of the object file is reached (See Figure 23.) * Step 10: Disable programming access (PELCK mode) 8.9.5. Verify algorithm Verify must be done after each byte or block of bytes is programmed. In either case, a complete verify of the programmed array will ensure reliable programming of the T89C51RD2. P 2.7 is used to enable data output. To verify the T89C51RD2 code the following sequence must be exercised: * Step 1:Activate the combination of program and control signals (PGMV) * Step 2: Input the valid address on the address lines. * Step 3: Read data on the data lines. Repeat step 2 through 3 changing the address for the entire array verification (See Figure 23.). Programming Cycle Read/Verify Cycle A0-A15 D0-D7 Data In Data Out 48 clk (load latch ) or 10 ms (write) ALE/PROG EA 5V 0V Control signals P2.7 Figure 23. Programming and Verification Signal's Waveform 8.9.6. Extra memory mapping The memory mapping the T89C51RD2 software registers in the Extra FLASH memory is described in the table below. Table 34. Extra Row Memory Mapping (XAF) Copy of device ID #3 Rev. F - 15 February, 2001 Address Default content 0061h FFh 68 T89C51RD2 Table 34. Extra Row Memory Mapping (XAF) Copy of device ID #2 Copy of device ID #1 Copy of Manufacturer Code: ATMEL 0060h FCh 0031h D7h 0030h 58h Boot reference 0006h Software Security Byte (level 1 by default) 0005h FFh Copy of HSB (level 4 by default and BLJB = 0) 0004h 18h or 1Bh Software Boot Vector 0001h FCh Boot Status Byte 0000h FFh All other addresses are reserved 69 Rev. F - 15 February, 2001 T89C51RD2 9. Electrical Characteristics 9.1. Absolute Maximum Ratings (1) Ambiant Temperature Under Bias: C = commercial 0C to 70C I = industrial -40C to 85C Storage Temperature -65C to +150C Voltage on VCC VSS-0.5 V to +6.5V Voltage on Any Pin VSS-0.5 V to VCC+0.5 V Power Dissipation 1 W(2) NOTES 1. Stresses at or above those listed under " Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions may affect device reliability. 2. This value is based on the maximum allowable die temperature and the thermal resistance of the package. Rev. F - 15 February, 2001 70 T89C51RD2 9.2. DC Parameters for Standard Voltage (1) TA = 0C to +70C; VSS = 0 V; VCC = 5 V 10%; F = 0 to 40 MHz. TA = -40C to +85C; VSS = 0 V; VCC = 5 V 10%; F = 0 to 40 MHz. Symbol Parameter VIL Input Low Voltage VIH Input High Voltage except XTAL1, RST VIH1 Input High Voltage, XTAL1, RST VOL Output Low Voltage, ports 1, 2, 3, 4 and 5 (6) VOL1 VOH Min Max Unit -0.5 0.2 VCC - 0.1 V 0.2 VCC + 0.9 VCC + 0.5 V 0.7 VCC VCC + 0.5 V 0.3 0.45 1.0 V V V IOL = 100 A(4) 0.3 0.45 1.0 V V V IOL = 200 A(4) Typ (5) Output Low Voltage, port 0, ALE, PSEN (6) Output High Voltage, ports 1, 2, 3, 4 and 5 VCC - 0.3 V V V VCC - 0.7 VCC - 1.5 VOH1 Output High Voltage, port 0, ALE, PSEN VCC - 0.3 V V V VCC - 1.5 RST Pulldown Resistor 50 IOL = 1.6 mA(4) IOL = 3.5 mA(4) IOL = 3.2 mA(4) IOL = 7.0 mA(4) IOH = -10 A IOH = -30 A IOH = -60 A VCC = 5 V 10% VCC - 0.7 RRST Test Conditions IOH = -200 A IOH = -3.2 mA IOH = -7.0 mA VCC = 5 V 10% 90 200 k IIL Logical 0 Input Current ports 1, 2, 3, 4 and 5 -50 A Vin = 0.45 V ILI Input Leakage Current 10 A 0.45 V < Vin < VCC ITL Logical 1 to 0 Transition Current, ports 1, 2, 3, 4 and 5 -650 A Vin = 2.0 V CIO Capacitance of I/O Buffer 10 pF Fc = 1 MHz TA = 25C IPD Power Down Current 150 A VCC = 3 V to 5.5 V(3) Power Supply Current onnormal mode 0.7 Freq (MHz) + 3 mA mA VCC = 5.5 V(1) Power Supply Current on idle mode 0.4 Freq (MHz) + 2 mA mA VCC = 5.5 V(2) ICCOP ICCIDLE 120 Table 35. DC Parameters in Standard Voltage (1) 71 Rev. F - 15 February, 2001 T89C51RD2 9.3. DC Parameters for Standard Voltage (2) TA = 0C to +70C; VSS = 0 V; VCC = 3 V to 5.5 V; F = 0 to 33 MHz. TA = -40C to +85C; VSS = 0 V; VCC = 3 V to 5.5 V; F = 0 to 33 MHz. Symbol Parameter Min Max Unit -0.5 0.2 VCC - 0.1 V 0.2 VCC + 0.9 VCC + 0.5 V 0.7 VCC VCC + 0.5 V Typ(5) Test Conditions VIL Input Low Voltage VIH Input High Voltage except XTAL1, RST VIH1 Input High Voltage, XTAL1, RST VOL Output Low Voltage, ports 1, 2, 3, 4 and 5 (6) 0.45 V IOL = 0.8 mA(4) VOL1 Output Low Voltage, port 0, ALE, PSEN (6) 0.45 V IOL = 1.6 mA(4) VOH Output High Voltage, ports 1, 2, 3, 4 and 5 0.9 VCC V IOH = -10 A VOH1 Output High Voltage, port 0, ALE, PSEN 0.9 VCC V IOH = -40 A IIL Logical 0 Input Current ports 1, 2, 3, 4 and 5 -50 A Vin = 0.45 V ILI Input Leakage Current 10 A 0.45 V < Vin < VCC ITL Logical 1 to 0 Transition Current, ports 1, 2, 3, 4 and 5 -650 A Vin = 2.0 V 200 k 10 pF Fc = 1 MHz TA = 25C 150 A VCC = 3 V to 5.5 V(3) 0.7 Freq (MHz) + 3 mA mA VCC = 5.5 V(1) 0.5 Freq (MHz) + 2 mA mA VCC = 5.5 V(2) RRST RST Pulldown Resistor CIO Capacitance of I/O Buffer IPD Power Down Current ICCOP ICCIDLE 50 90 120 Power Supply Current on normal mode Power Supply Current on idle mode Table 36. DC Parameters for Standard Voltage (2) Rev. F - 15 February, 2001 72 T89C51RD2 9.4. DC Parameters for Low Voltage TA = 0C to +70C; VSS = 0 V; VCC = 2.7 V to 3.6 V; F = 0 to 25 MHz. TA = -40C to +85C; VSS = 0 V; VCC = 2.7 V to 3.6 V; F = 0 to 25 MHz. Symbol Parameter Min Max Unit -0.5 0.2 VCC - 0.1 V 0.2 VCC + 0.9 VCC + 0.5 V 0.7 VCC VCC + 0.5 V Typ(5) Test Conditions VIL Input Low Voltage VIH Input High Voltage except XTAL1, RST VIH1 Input High Voltage, XTAL1, RST VOL Output Low Voltage, ports 1, 2, 3, 4 and 5 (6) 0.45 V IOL = 0.8 mA(4) VOL1 Output Low Voltage, port 0, ALE, PSEN (6) 0.45 V IOL = 1.6 mA(4) VOH Output High Voltage, ports 1, 2, 3, 4 and 5 0.9 VCC V IOH = -10 A VOH1 Output High Voltage, port 0, ALE, PSEN 0.9 VCC V IOH = -40 A IIL Logical 0 Input Current ports 1, 2, 3, 4 and 5 -50 A Vin = 0.45 V ILI Input Leakage Current 10 A 0.45 V < Vin < VCC ITL Logical 1 to 0 Transition Current, ports 1, 2, 3, 4 and 5 -650 A Vin = 2.0 V 200 k 10 pF Fc = 1 MHz TA = 25C 50 A VCC = 2.7 V to 3.6 V(3) 0.6 Freq (MHz) + 3 mA mA VCC = 3.6 V(1) 0.3 Freq (MHz) + 2 mA mA VCC = 3.6 V(2) RRST RST Pulldown Resistor CIO Capacitance of I/O Buffer IPD Power Down Current ICCOP ICCIDLE 50 90 1 Power Supply Current on normal mode Power Supply Current on idle mode Table 37. DC Parameters for Low Voltage NOTES 1. Operating ICC is measured with all output pins disconnected; XTAL1 driven with TCLCH, TCHCL = 5 ns (see Figure 27.), VIL = VSS + 0.5 V, VIH = VCC - 0.5V; XTAL2 N.C.; EA = RST = Port 0 = VCC. ICC would be slightly higher if a crystal oscillator used (see Figure 24.). 2. Idle ICC is measured with all output pins disconnected; XTAL1 driven with TCLCH, TCHCL = 5 ns, VIL = VSS + 0.5 V, VIH = VCC - 0.5 V; XTAL2 N.C; Port 0 = VCC; EA = RST = VSS (see Figure 25.). 3. Power Down ICC is measured with all output pins disconnected; EA = VSS, PORT 0 = VCC; XTAL2 NC.; RST = VSS (see Figure 26.). In addition, the WDT must be inactive and the POF flag must be set. 4. Capacitance loading on Ports 0 and 2 may cause spurious noise pulses to be superimposed on the VOLs of ALE and Ports 1 and 3. The noise is due to external bus capacitance discharging into the Port 0 and Port 2 pins when these pins make 1 to 0 transitions during bus operation. In the worst cases (capacitive loading 100pF), the noise pulse on the ALE line may exceed 0.45V with maxi VOL peak 0.6V. A Schmitt Trigger use is not necessary. 5. Typicals are based on a limited number of samples and are not guaranteed. The values listed are at room temperature.. 6. Under steady state (non-transient) conditions, IOL must be externally limited as follows: Maximum IOL per port pin: 10 mA Maximum IOL per 8-bit port: Port 0: 26 mA Ports 1, 2 and 3: 15 mA Maximum total IOL for all output pins: 71 mA If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test conditions. 73 Rev. F - 15 February, 2001 T89C51RD2 VCC ICC VCC VCC P0 VCC RST EA XTAL2 XTAL1 (NC) CLOCK SIGNAL VSS All other pins are disconnected. Figure 24. ICC Test Condition, Active Mode VCC ICC VCC VCC P0 RST EA XTAL2 XTAL1 VSS (NC) CLOCK SIGNAL All other pins are disconnected. Figure 25. ICC Test Condition, Idle Mode VCC ICC VCC VCC P0 RST (NC) EA XTAL2 XTAL1 VSS All other pins are disconnected. Figure 26. ICC Test Condition, Power-Down Mode Rev. F - 15 February, 2001 74 T89C51RD2 VCC-0.5V 0.45V TCLCH TCHCL TCLCH = TCHCL = 5ns. 0.7VCC 0.2VCC-0.1 Figure 27. Clock Signal Waveform for ICC Tests in Active and Idle Modes 9.5. AC Parameters 9.5.1. Explanation of the AC Symbols Each timing symbol has 5 characters. The first character is always a "T" (stands for time). The other characters, depending on their positions, stand for the name of a signal or the logical status of that signal. The following is a list of all the characters and what they stand for. Example:TAVLL = Time for Address Valid to ALE Low. TLLPL = Time for ALE Low to PSEN Low. TA TA TA TA = = = = 0 to +70C; VSS = 0 V; VCC = 5 V 10%; M range. -40C to +85C; VSS = 0 V; VCC = 5 V 10%; M range. 0 to +70C; VSS = 0 V; 2.7 V < VCC < 3.3 V; L range. -40C to +85C; VSS = 0 V; 2.7 V < VCC < 3.3 V; L range. AC characteristics of -M parts at 3 volts are similar to -L parts (Load Capacitance for port 0, ALE and PSEN = 100 pF; Load Capacitance for all other outputs = 80 pF.) Table 38, Table 41 and Table 44 give the description of each AC symbols. Table 39, Table 42 and Table 45 give for each range the AC parameter. Table 40, Table 43 and Table 46 give the frequency derating formula of the AC parameter for each speed range description. To calculate each AC symbols. take the x value in the correponding column (-M or -L) and use this value in the formula. Example: TLLIU for -M and 20 MHz, Standard clock. x = 35 ns T = 50 ns TCCIV = 4T - x = 165 ns 75 Rev. F - 15 February, 2001 T89C51RD2 9.5.2. External Program Memory Characteristics Table 38. Symbol Description Symbol Parameter T Oscillator clock period TLHLL ALE pulse width TAVLL Address Valid to ALE TLLAX Address Hold After ALE TLLIV ALE to Valid Instruction In TLLPL ALE to PSEN TPLPH PSEN Pulse Width TPLIV PSEN to Valid Instruction In TPXIX Input Instruction Hold After PSEN TPXIZ Input Instruction FloatAfter PSEN TAVIV Address to Valid Instruction In TPLAZ PSEN Low to Address Float Table 39. AC Parameters for a Fix Clock Symbol -M Min -L Max Min Units Max T 25 25 ns TLHLL 40 40 ns TAVLL 10 10 ns TLLAX 10 10 ns TLLIV 70 70 ns TLLPL 15 15 ns TPLPH 55 55 ns TPLIV TPXIX 35 0 35 0 ns ns TPXIZ 18 18 ns TAVIV 85 85 ns TPLAZ 10 10 ns Rev. F - 15 February, 2001 76 T89C51RD2 Table 40. AC Parameters for a Variable Clock Symbol Type Standard Clock X2 Clock X parameter for -M range X parameter for -L range Units TLHLL Min 2T-x T-x 10 10 ns TAVLL Min T-x 0.5 T - x 15 15 ns TLLAX Min T-x 0.5 T - x 15 15 ns TLLIV Max 4T-x 2T-x 30 30 ns TLLPL Min T-x 0.5 T - x 10 10 ns TPLPH Min 3T-x 1.5 T - x 20 20 ns TPLIV Max 3T-x 1.5 T - x 40 40 ns TPXIX Min x x 0 0 ns TPXIZ Max T-x 0.5 T - x 7 7 ns TAVIV Max 5T-x 2.5 T - x 40 40 ns TPLAZ Max x x 10 10 ns 9.5.3. External Program Memory Read Cycle 12 TCLCL TLHLL TLLIV ALE TLLPL TPLPH PSEN TLLAX TAVLL PORT 0 INSTR IN TPLIV TPLAZ A0-A7 TPXAV TPXIZ TPXIX INSTR IN A0-A7 INSTR IN TAVIV PORT 2 77 ADDRESS OR SFR-P2 ADDRESS A8-A15 ADDRESS A8-A15 Rev. F - 15 February, 2001 T89C51RD2 9.5.4. External Data Memory Characteristics Table 41. Symbol Description Symbol Parameter TRLRH RD Pulse Width TWLWH WR Pulse Width TRLDV RD to Valid Data In TRHDX Data Hold After RD TRHDZ Data Float After RD TLLDV ALE to Valid Data In TAVDV Address to Valid Data In TLLWL ALE to WR or RD TAVWL Address to WR or RD TQVWX Data Valid to WR Transition TQVWH Data set-up to WR High TWHQX Data Hold After WR TRLAZ RD Low to Address Float TWHLH RD or WR High to ALE high Rev. F - 15 February, 2001 78 T89C51RD2 Table 42. AC Parameters for a Fix Clock Symbol -M Min Max Min Units Max TRLRH 130 130 ns TWLWH 130 130 ns TRLDV TRHDX 100 0 100 0 ns ns TRHDZ 30 30 ns TLLDV 160 160 ns TAVDV 165 165 ns 100 ns TLLWL 50 TAVWL 75 75 ns TQVWX 10 10 ns TQVWH 160 160 ns TWHQX 15 15 ns TRLAZ TWHLH 79 -L 100 50 0 10 40 10 0 ns 40 ns Rev. F - 15 February, 2001 T89C51RD2 Table 43. AC Parameters for a Variable Clock Symbol Type Standard Clock X2 Clock X parameter for -M range X parameter for -L range Units TRLRH Min 6T-x 3T-x 20 20 ns TWLWH Min 6T-x 3T-x 20 20 ns TRLDV Max 5T-x 2.5 T - x 25 25 ns TRHDX Min x x 0 0 ns TRHDZ Max 2T-x T-x 20 20 ns TLLDV Max 8T-x 4T -x 40 40 ns TAVDV Max 9T-x 4.5 T - x 60 60 ns TLLWL Min 3T-x 1.5 T - x 25 25 ns TLLWL Max 3T+x 1.5 T + x 25 25 ns TAVWL Min 4T-x 2T-x 25 25 ns TQVWX Min T-x 0.5 T - x 15 15 ns TQVWH Min 7T-x 3.5 T - x 15 15 ns TWHQX Min T-x 0.5 T - x 10 10 ns TRLAZ Max x x 0 0 ns TWHLH Min T-x 0.5 T - x 15 15 ns TWHLH Max T+x 0.5 T + x 15 15 ns 9.5.5. External Data Memory Write Cycle TWHLH ALE PSEN TLLWL TWLWH WR TLLAX PORT 0 A0-A7 TQVWX TQVWH TWHQX DATA OUT TAVWL PORT 2 ADDRESS OR SFR-P2 Rev. F - 15 February, 2001 ADDRESS A8-A15 OR SFR P2 80 T89C51RD2 9.5.6. External Data Memory Read Cycle TWHLH TLLDV ALE PSEN TLLWL TRLRH RD TRHDZ TAVDV TLLAX PORT 0 TAVWL PORT 2 TRHDX A0-A7 ADDRESS OR SFR-P2 DATA IN TRLAZ ADDRESS A8-A15 OR SFR P2 9.5.7. Serial Port Timing - Shift Register Mode Table 44. Symbol Description Symbol Parameter TXLXL Serial port clock cycle time TQVHX Output data set-up to clock rising edge TXHQX Output data hold after clock rising edge TXHDX Input data hold after clock rising edge TXHDV Clock rising edge to input data valid Table 45. AC Parameters for a Fix Clock Symbol -M Min Max Min Max TXLXL 300 300 ns TQVHX 200 200 ns TXHQX 30 30 ns TXHDX 0 0 ns TXHDV 81 Units -L 117 117 ns Rev. F - 15 February, 2001 T89C51RD2 Table 46. AC Parameters for a Variable Clock X parameter for -M range Units Symbol Type Standard Clock X2 Clock X parameter for -L range TXLXL Min 12 T 6T TQVHX Min 10 T - x 5T-x 50 50 ns TXHQX Min 2T-x T-x 20 20 ns TXHDX Min x x 0 0 ns TXHDV Max 10 T - x 5 T- x 133 133 ns ns 9.5.8. Shift Register Timing Waveforms INSTRUCTION 0 1 2 3 4 5 6 7 8 ALE TXLXL CLOCK TXHQX TQVXH OUTPUT DATA 0 WRITE to SBUF TXHDV INPUT DATA CLEAR RI Rev. F - 15 February, 2001 1 2 3 4 5 6 7 TXHDX VALID VALID VALID SET TI VALID VALID VALID VALID VALID SET RI 82 T89C51RD2 9.5.9. FLASH EEPROM Programming and Verification Characteristics TA = 21C to 27C; VSS = 0V; VCC = 5V 10%. Table 47. Flash Programming Parameters Symbol 1/TCLCL Parameter Min Max Units 4 6 MHz Oscillator Frquency TEHAZ Control to address float 48 TCLCL TAVGL Address Setup to PROG Low 48 TCLCL TGHAX Adress Hold after PROG 48 TCLCL TDVGL Data Setup to PROG Low 48 TCLCL TGHDX Data Hold after PROG 48 TCLCL TGLGH PROG Width for PGMC and PGXC* TGLGH PROG Width for PGML TAVQV Address to Valid Data 48 TCLCL TELQV ENABLE Low to Data Valid 48 TCLCL TEHQZ Data Float after ENABLE 10 20 ms 48 TCLCL 0 48 TCLCL 9.5.10. FLASH EEPROM Programming and Verification Waveforms PROGRAMMING VERIFICATION ADDRESS ADDRESS P1.0-P1.7 P2.0-P2.4 P3.4-P3.5 TAVQV P0 DATA OUT DATA IN TGHDX TGHAX TDVGL TAVGL ALE/PROG TGLGH CONTROL SIGNALS (ENABLE) 83 TEHAZ TELQV TEHQZ Rev. F - 15 February, 2001 T89C51RD2 9.5.11. External Clock Drive Characteristics (XTAL1) Symbol Parameter Min Max Units TCLCL Oscillator Period 25 ns TCHCX High Time 5 ns TCLCX Low Time 5 ns TCLCH Rise Time 5 ns TCHCL Fall Time 5 ns 60 % TCHCX/TCLCX Cyclic ratio in X2 mode 40 Table 48. AC Parameters 9.5.12. External Clock Drive Waveforms VCC-0.5V 0.45V 0.7VCC 0.2VCC-0.1 TCHCX TCLCH TCLCX TCHCL TCLCL 9.5.13. AC Testing Input/Output Waveforms VCC -0.5 V 0.2 VCC + 0.9 INPUT/OUTPUT 0.2 VCC - 0.1 0.45 V AC inputs during testing are driven at VCC - 0.5 for a logic "1" and 0.45V for a logic "0". Timing measurement are made at VIH min for a logic "1" and VIL max for a logic "0". 9.5.14. Float Waveforms FLOAT VOH - 0.1 V VOL + 0.1 V VLOAD VLOAD + 0.1 V VLOAD - 0.1 V For timing purposes as port pin is no longer floating when a 100 mV change from load voltage occurs and begins to float when a 100 mV change from the loaded VOH/VOL level occurs. IOL/IOH 20mA. Rev. F - 15 February, 2001 84 T89C51RD2 9.5.15. Clock Waveforms Valid in normal clock mode. In X2 mode XTAL2 must be changed to XTAL2/2. INTERNAL CLOCK STATE4 STATE5 STATE6 STATE1 STATE2 STATE3 STATE4 STATE5 P1 P1 P1 P1 P1 P1 P1 P1 P2 P2 P2 P2 P2 P2 P2 P2 XTAL2 ALE THESE SIGNALS ARE NOT ACTIVATED DURING THE EXECUTION OF A MOVX INSTRUCTION EXTERNAL PROGRAM MEMORY FETCH PSEN P0 DATA SAMPLED FLOAT P2 (EXT) PCL OUT DATA SAMPLED FLOAT PCL OUT DATA SAMPLED FLOAT PCL OUT INDICATES ADDRESS TRANSITIONS READ CYCLE RD PCL OUT (IF PROGRAM MEMORY IS EXTERNAL) P0 DPL OR Rt OUT DATA SAMPLED FLOAT INDICATES DPH OR P2 SFR TO PCH TRANSITION P2 WRITE CYCLE WR P0 PCL OUT (EVEN IF PROGRAM MEMORY IS INTERNAL) DPL OR Rt OUT PCL OUT (IF PROGRAM MEMORY IS EXTERNAL) DATA OUT P2 INDICATES DPH OR P2 SFR TO PCH TRANSITION PORT OPERATION MOV PORT SRC OLD DATA NEW DATA P0 PINS SAMPLED P0 PINS SAMPLED MOV DEST P0 MOV DEST PORT (P1. P2. P3) (INCLUDES INTO. INT1. TO T1) SERIAL PORT SHIFT CLOCK P1, P2, P3 PINS SAMPLED RXD SAMPLED P1, P2, P3 PINS SAMPLED RXD SAMPLED TXD (MODE 0) This diagram indicates when signals are clocked internally. The time it takes the signals to propagate to the pins, however, ranges from 25 to 125 ns. This propagation delay is dependent on variables such as temperature and pin loading. Propagation also varies from output to output and component. Typically though (TA=25C fully loaded) RD and WR propagation delays are approximately 50ns. The other signals are typically 85 ns. Propagation delays are incorporated in the AC specifications. 85 Rev. F - 15 February, 2001 T89C51RD2 10. Ordering Information T 89C51RD2 -3C Packages: 3C: PDIL40 SL: PLCC44 RL: VQFP44 (1.4mm) SM: PLCC68 RD: VQFP64, squarepackage (1.4mm) DD: Dice in ship tray M C S Temperature Range C: Commercial 0 to 70oC I: Industrial -40 to 85oC 89C51RD2 (64k Flash) Conditioning S: Stick T: Tray R: Tape & Reel U: Stick + Dry Pack V: Tray + Dry Pack F: Tape & Reel + Dry Pack B: Blue Tape W: Wafer Rev. F - 15 February, 2001 -M: VCC: 4.5 to 5.5V 40MHz, X1 Mode 20MHz, X2 Mode VCC: 3 to 5.5V 33 MHz, X1 mode 16 MHz, X2 mode -L : VCC: 2.7 to 3.6 V 25 MHz, X1 mode 12 MHz, X2 mode 86