KING BILLION ELECTRONICS CO.， LTD 駿 億 電 子 股 份 有 限 公 司 HE89A20 HE80000 SERIES A. HE89A20 Introduction HE89A20 is a member of 8-bit Micro-controller series used for telephone communication developed by King Billion Electronics Ltd. The built-in DTMF generator can generate the PSTN dialing tone directly. It can be applicable as Small/ Medium class telephone or communication product etc.. The instruction set of HE89A20 are quite easy to learn and simple to use. Only about thirty instructions with four-type addressing mode are provided. Most of instructions take only 3 oscillator clocks (machine cycles). The processing power is enough to most of battery operation system. B. HE89A20 Features zOperation Voltage： 2.4V – 5.5V zSystem Clock： DC ~ 8MHz @ 5.0V z DC ~ 4MHz @ 2.4V zInternal ROM： 16K Bytes(16K Program ROM) zInternal RAM： 512 Bytes. zDual Clock System ： Normal (Fast) clock： 32.768K ~ 8MHz z Slow clock： 32.768KHz zOperation Mode： DUAL、FAST、SLOW、IDLE、SLEEP Mode. zWith WDT (WATCH DOG TIMER) to prevent deadlock condition.. z32 bit Bi-directional I/O port. Mask Option can select PUSH-PULL or OPEN DRAIN output mode for each I/O pin. zBuilt-in DTMF Generator. zTwo external interrupts and three internal timer interrupts. zTwo 16-bit timers and one Time Base timer. zInstruction set： 32 instructions, 4 addressing mode. 9-bit DATA POINTER for RAM and 14-bit TABLE POINTER for ROM. 1 V3.1E