General Description

The EM78869 is an 8-bit RISC type microprocessor with low power, high speed CMOS technology. Integrated into the single chip are on chip watchdog (WDT), RAM, ROM, programmable real-time clock/counter, internal interrupt, power-down mode, LCD driver, and tri-state I/O. The EM78869 provides a single chip solution for designing DATA-BANK of message display.

Features

CPU

Operating voltage range:2.2V ~ 5.5V

„Operating temperature range:–20°C ~ +70°C.

32.768KHz Crystal/RC oscillation circuit selected by code option for system clock

144 byte general purpose register

640 x 8 bits on-chip data RAM

8K x 13 on-chip mask type program ROM.

Up to 29 bi-directional tri-state I/O ports

8-level stack for subroutine nesting

8-bit real time clock/counter (TCC)

Programmable free running on-chip watchdog timer

Port key scan function

Operation mode:a) Normal mode; b) Green mode; c).Idle mode; d) Sleep mode

Input port wake-up function (Port 9)

7 interrupt sources:

•4 external (INT0 ~ INT3)

•3 internal (one TCC timer overflow interrupt + two 8-bit counters overflow interrupt)

64-pin chip form (EM78869)

Applications

Data Bank

Message display box

Scientific calculator