EM78871
8-bit Micro-controller
I.General Description
The EM78871 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, program ROM, programmable real time
clock/counter, external/internal interrupt, power down mode, LCD driver, FSK decoder, Call waiting decoder, DTMF
receiver, Programming Tone generator, build-in KEY TONE clock generation, Comparator and tri-state I/O. The
EM78871 provides a single chip solution to design a CID of calling message display.
II.Feature
ꢁCPU
‧ Operating voltage range : 2.2V~5.5V(Normal mode), 2.0V~5.5V(Green mode)
‧ 32K×13 on chip Program ROM
‧ 4K×8 on chip data RAM
‧ 144 byte working register
‧ Up to 51 bi-directional tri-state I/O ports (32 shared with LCD Segment pins)
‧ IO with internal Pull high, wake-up and interrupt functions
‧ STACK: 32 level stack for subroutine nesting
‧ TCC: 8-bit real time clock/counter (TCC) with 8-bit prescaler
‧ COUNTER1: 8-bit counter with 8-bit prescaler can be an interrupt source
‧ COUNTER2: 8-bit counter with 8-bit prescaler can be an interrupt source
‧ Watch Dog : Programmable free running on chip watchdog timer
‧ CPU modes:
Mode
Sleep mode
Green mode
CPU status
Turn off
Turn on
Main clock
Turn off
Turn off
Turn on
32.768kHz clock status
Turn off
Turn on
Normal mode Turn on
Turn on
‧ 13 interrupt source , 8 external , 5 internal
‧ Key Scan : Port key scan function up to 16x4 keys
‧ Sub-Clock: 32.768KHz crystal
‧ Main-clock: 3.5862MHz multiplied by 0.25, 0.5, 1 or 3 generated by internal PLL
‧ Key tone output :4KHz, 2KHz ,1KHz (shared with IO)
‧ Comparator: 3-channel comparators: internal (16 level) or external reference voltage. (shared with IO)
‧ Serial Peripheral Interface (SPI): Interrupt flag available for the read buffer full, Programmable baud rates of
communication, Three-wire synchronous communication. (shared with IO)
ꢁCurrent D/A
‧ Operation Voltage : 2.5V∼ 5.5V
‧ 7-bit resolution and 3-bit output level control
‧ Current DA output can drive speaker through a transistor for sound playing. (shared with IO)
ꢁProgrammable Tone Generators
‧ Operation Voltage 2.2V∼ 5.5V
‧ Programmable Tone1 and Tone2 generators
‧ Independent single tone generation for Tone1 and Tone2
‧ Mixed dual tone generation by Tone1 and Tone2 with 2dB difference
‧ Can be programmed for DTMF tone generation
‧ Can be programmed for FSK signal (Bell202 or V.23) generation
ꢁCID
‧ Operation Voltage 2.7V∼ 5.5V for FSK
‧ Operation Voltage 2.7V∼ 5.5V for DTMF receiver
‧ Compatible with Bellcore GR-30-CORE (formerly as TR-NWT-000030)
‧ Compatible with British Telecom (BT) SIN227 & SIN242
‧ FSK demodulator for Bell 202 and ITU-T V.23 (formerly as CCITT V.23)
ꢁCALL WAITING
‧ Operation Voltage 2.6V∼ 5.5V
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* This specification is subject to be changed without notice.
4
8/23/04 (V1.5)
ELAN [ ELAN MICROELECTRONICS CORP ]
