General Description

The EM78862B 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 EM78862B provides a single chip solution for designing DATA-BANK of message display.

Features

CPU

„ Operating voltage range: 2.2V ~ 5.5V

„ 16K X 13 on chip ROM

„ 2.2K X 8 on chip RAM

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

„ 8 level stack for subroutine nesting

„ 8-bit real time clock/counter (TCC)

„ Two sets of 8 bit counters can be interrupt sources

„ Programmable free running on chip watchdog timer

„ Four modes (internal PLL clock 3.579MHz)

   •SLEEP Mode: CPU and 3.579MHz clock turn off, 32.768KHz clock turn off

   •IDLE Mode: CPU and 3.579MHz clock turn off, 32.768KHz clock turn on

   •GREEN Mode: 3.579MHz clock turn off, CPU and 32.768KHz clock turn on

   •NORMAL Mode:3.579MHz clock turn on, CPU and 32.768KHz clock turn on

„ Input port wake up function

„ Seven interrupt sources; 4 external, 3 internal

„ 84-pin chip (EM78862BH)

„ Port key scan function

„ Clock frequency 32.768KHz or RC mode

„ Eight R-option pins

LCD

„ Software selectable LCD operation voltage

„ Common driver pins:9

„ Segment driver pins:60

 „1/4 bias

„ 1/8, 1/9 duty

Applications

„Data Bank

Message display box

„Scientific calculator