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