GENERAL DESCRIPTION

The EM78860 is an 8-bit RISC type microprocessor with low power , high speed CMOS technology . Integrated onto a 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 EM78860 provides a single chip solution to design a message display .

FEATURES

CPU

• Operating voltage range : 2.5V~5.5V

• 16Kx13 on chip ROM

• 2.8Kx8 on chip RAM

• Up to 32 bi-directional 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

• Selective signal sources and with overflow interrupt

• Programmable free running on chip watchdog timer

• 99.9 single instruction cycle commands

• Four modes (internal clock 3.679MHz, external 32.768KHz)

1. Sleep mode : CPU and 3.679MHz clock turn off, 32.768KHz clock turn off

2. Idle mode : CPU and 3.679MHz clock turn off, 32.768KHz clock turn on

3. Green mode : 3.679MHz clock turn off, CPU and 32.768KHz clock turn on

4. Normal mode : 3.679MHz clock turn on , CPU and 32.768KHz clock turn on

• Low battery detector

• Input port wake up function

• 8 interrupt source , 4 external , 3 internal

• 100 pin QFP or chip

• Port key scan function

• Port interrupt , pull high and open drain functions

• Clock frequency 32.768KHz externally

LCD

• LCD operation voltage chosen by software

• Common driver pins : 16

• Segment driver pins : 60

• 1/4 bias

• 1/8,1/16 duty

APPLICATION

1. adjunct units

2. data bank