General Description
The EM78911 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 ,CALL WAITING decoder, DTMF generator and tri-state I/O . The EM78911 provides a single chip solution to design a CID of calling message_display .

Feature
CPU
 • Operating voltage range : 2.5V〜5.5V
 • 16K× 13 on chip ROM
 • 2.8K× 8 on chip RAM
 • Up to 36 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
 • Four modes (internal clock 3.579MHz)
    1. Sleep mode : CPU and 3.579MHz clock turn off, 32.768KHz clock turn off
    2. Idle mode : CPU and 3.579MHz clock turn off, 32.768KHz clock turn on
    3. Green mode : 3.579MHz clock turn off, CPU and 32.768KHz clock turn on
    4. Normal mode : 3.579MHz clock turn on , CPU and 32.768KHz clock turn on
 • Ring on voltage detector and low battery detector
 • Input port wake up function
 • 9 interrupt source , 4 external , 5 internal
 • 100 pin QFP or chip
 • Port key scan function
 • Clock frequency 32.768KHz
 • Eight R-option pins

CID
 • Operation Volltage 3.5 〜6V for FSK
 • Operation Volltage 2.5 〜6V for DTMF
 • Bell 202 , V.23 FSK demodulator
 • DTMF generator
 • Ring detector on chip

CALL WAITING
 • Operation Volltage 3.6 〜5.5V
 • Compatible with Bellcore special report SR-TSV-002476
 • Call-Waiting (2130Hz plus 2750Hz) Alert Signal Detector
 • Good talkdown and talkoff performance
 • Sensitivity compensated by adjusting input OP gain

LCD
 • LCD operation voltage chosen by software
 • Common driver pins : 16
 • Segment driver pins : 60
 • 1/4 bias

Application
1. adjunct units
2. answering machines
3. feature phones