GENERAL DESCRIPTION
The EM78811 is an 8-bit CID (Call Identification) 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 , FSK decoder , DTMF generator and tri-state I/O . The EM78811 provides a single chip solution to design a CID of calling message_display .

FEATURES
CPU
• Operating voltage range : 2.5V~5.5V
• 16K X13 on chip ROM
• 2.8K X 8 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 trigger edges , and with overflow interrupt
• Programmable free running on chip watchdog timer
• 99.9% single instruction cycle commands
• Three modes (internal clock 3.679MHz)
   1. sleep mode : CPU and 3.679MHz clock turn off, 32.768KHz clock turn off
   2. Idle mode : CPU and 3.679 MHz 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
• Ring on voltage detector and low battery detector
• Input port wake up function
• 8 interrupt source , 4 external , 4 internal
• 100 QFP or chip
• Port key scan function
• Port interrupt, Pull high and Open drain functions
• Clock frequency 32.768KHz
• Main clock can switch to 1.84MHz by code option

CID
• Operation Volltage 3.5 ~5.5V for FSK
• Operation Volltage 2.5 ~5.5V for DTMF
• Bell 202 , V.23 FSK demodulator
• DTMF generator
• Ring detector on chip

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. answering machines
3. feature phones