GENERAL DESCRIPTIONTM57PA20/20A/20B/40都是一个8位元高性能OTP单片机，采用CMOS制成，具有高效能、
低耗电以及高抗噪声能力特点。它的核心是RISC-like的架构,只需36个指令，并具有内建高低
频,RC振荡器、多通道A/D转换器、PWM的输出控制、可灵活调整的计时器/计数器。它强大的
功能使得它可以广泛应用在A/D产品中，例如传感器信号处理、小家电控制、消费性产品和子系
统控制等等。从表1-1中可以比较出TM57PA20/20A/20B/40之间的差异。
FEATURES1. ROM:
TM57PA20: 2K x 14 bits OTP
TM57PA20A/B: 2K x 14 bits OTP
TM57PA40: 4K x 14 bits OTP or 2K x 14 bits TTP™ (Two Time Programmable ROM)
2. RAM: 184 x 8 bits
3. STACK: 6 Levels
4. I/O ports: Three Programmable I/O ports (Max. 18 pins)
5. Timer0/Counter: 8-bit timer/counter with divided by 1~256 pre-scale option
6. Timer1: 8-bit auto-reloadable timer with divided by 1~256 pre-scale option
7. Two 8+2 bit PWM channels capable of 1024 duty resolution
8. 12-bit ADC with 8 channel input
9. Buzzer output
10. Watchdog/Wakeup Timer: On chip Timer based on internal RC oscillation, 13~140 ms wakeup time
11. Reset: Power On Reset, Watchdog Reset, Low Voltage Reset, External pin Reset
12. System Clock Mode:
(1) Slow Crystal: 32 KHz
(2) Fast Crystal: 455 KHz ~24 MHz
(3) Internal RC: 4 MHz
(4) External RC
13. 2-Level Low Voltage Reset: 3.1V
14. Operation Voltage: Low Voltage Reset Level to 5.5V
(1) fosc = 4 MHz, 2.4V ~ 5.5V
(2) fosc = 8 MHz, 2.4V ~ 5.5V
(3) fosc = 12 MHz, 2.8V ~ 5.5V
(4) fosc = 16 MHz, 3.0V ~ 5.5V
15. Instruction set: 36 Instructions
16. Interrupts: Three pin interrupts, Timer0/Timer1 interrupt and Wakeup Timer interrupt
17. Power Down mode support
18. Package Types: 16-DIP/SOP, 20-DIP/SOP
19. Supported EV board on ICE
EV board: EV2795