GENERAL DESCRIPTION

The W742E/C811 (W742C811 is mask type, W742E811 is electrical erasable EPROM type) is a highperformance 4-bit microcontroller (mC) 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, and one channel DTMF generator. There are also eleven interrupt sources and 16-level stack buffer. The W742E/C811 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 – 5.5V for mask type

- 2.4V – 4.8V for electrical erasable EPROM 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

- 16384(16K) 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 nonmodulating 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 dialling

? 8-bit Serial I/O Interface

- 8-bit transmit/receive mode by internal or external clock source

? Two Built-in 14-bit Frequency Dividers

- Divider0: the clock source is the main oscillator (Fosc)

- Divider1: the clock source is the sub-oscillator (Fs)

? Two Built-in 8-bit Programmable Countdown Tmers

- Timer 0: one of two internal clock frequencies (FOSC/4 or FOSC/1024) can be selected

- Timer 1: with auto-reload function and one of two internal clock frequencies (FOSC or FOSC/64 or Fs) can be selected (signal output through MFP pin)

? Built-in 18/15-bit Watchdog Timer Selectable for System Reset, Enable/Disable by Code Option

? Powerful Instruction Set

? 16-level Stack Buffer

? Packaged in 100-pin QFP