GENERAL DESCRIPTION

The W742E/C816 [W742E 816 is EEPROM type, W742C816 is mask type] is a high-performance 4-bit microcontroller (µC) that built in 640-dot LCD driver. The device contains a 4-bit ALU, two 8-bit timers, two dividers in dual-clock operation, a 40 × 16 LCD driver, ten 4-bit I/O ports (including 2 output port for LED driving), multiple frequency output, one channel DTMF generator and FSK modulator of CCITT V.23 or Bellcore 202. There are also eleven interrupt sources and 16-level stack buffer. The W742E/C816 operates on very low current and has three power reduction modes, hold mode, stop mode and slow mode, which help to minimize power dissipation.

FEATURES

• Operating voltage

− 2.4V - 6.0V for mask type

− 2.4V - 4.8V for EEPROM type

• Dual-clock operation

• Main oscillator

− 3.58 MHz or 400 KHz can be selected by code option

− Crystal or RC oscillator can be selected by code option

• Sub-oscillator

− Connect to 32.768 KHz crystal only

• Memory

− 32768(32K) x 16 bit program ROM (including 64K x 4 bit look-up table)

− 5120(5K) x 4 bit data RAM (including 16 nibbles x 16 pages working registers)

− 40 x 16 LCD data RAM

• 40 input/output pins

− Port for input only: 3 ports/12 pins

− Input/output ports: 3 ports/12 pins

− High sink current output port for LED driving: 2 port /8 pins

− DC output port: 2 ports/ 8 pins (selected by code option)

• Power-down mode

− Hold mode: no operation (main oscillator and sub-oscillator still operate)

− Stop mode: no operation (main oscillator and sub-oscillator are stopped)

− Slow mode: main oscillator is stopped, system is operated

by the sub-oscillator (32.768 KHz)

• Eleven interrupt sources

− Four internal interrupts (Divider0, Divider1, Timer 0, Timer 1)

− Seven external interrupts (RC.0 − 3, P1.2 (INT0 ), Serial Port, P1.3 (INT1))

• LCD driver output

− 40 segments x 16 commons

− 1/8 or 1/16 duty (selected by code option) 1/5 bias driving mode

− Clock source should be the sub-oscillator clock in the dual-clock operation mode

− 8 level software LCD contrast adjusting

− LCD operating voltage source could come from VDD or VLCD1 pin input

• MFP output pin

− Output is software controlled to generate modulating

or non-modulating frequency

− Works as frequency output specified by Timer 1

− Key tone generator

• DTMF output pin

− Output is one channel Dual Tone Multi-Frequency signal for dialing (Continue ...)