GENERAL DESCRIPTION

The W741C260 is a high-performance 4-bit microcontroller (mC) with an LCD driver. The device contains a 4-bit ALU, two 8-bit timers, two dividers, a 32 ´ 4 LCD driver, and five 4-bit I/O ports (including 1 output port to drive the LEDs). There are also five interrupt sources and 8-level subroutine nesting for interrupt applications. The W741C260 has two power reduction modes, hold mode and stop mode, which help to minimize power dissipation.

FEATURES

● Operating voltage: 2.2V to 5.5V (LCD drive voltage: 3.0V, or 4.5V)

● Operating frequency up to 4 MHz

● Crystal/RC oscillation circuit selectable by code option for system clock

● 32.768 KHz crystal oscillation circuit for sub-oscillator

● High-frequency clock (400 KHz to 4 MHz) or low-frequency clock (32.768 KHz) for crystal mode; selectable by code option

● Memory

- 2048 ´ 16 bit program ROM (including 2K ´ 4 bit look-up table)

- 128 ´ 4 bit data RAM (including 16 working registers)

- 32 ´ 4 LCD data RAM

● 21 input/output pins

- Ports for input only: 2 ports/8 pins

- Input/output ports: 2 ports/8 pins

- Port for output only: 1 port /4 pins (high sink current to drive LEDs)

- MFP output pin: 1 pin (MFP)

● Power-down mode

- Hold function: no operation (except for oscillator)

- Stop function: no operation (including main oscillator)

● Five types of interrupts

- Four internal interrupts (Divider 0, Divider 1, Timer 0, Timer 1)

- One external interrupt (Port RC)

● LCD driver output

- 32 segment ´ 4 common

- Static, 1/2 duty (1/2 bias), 1/3 duty (1/2 or 1/3 bias), 1/4 duty (1/3 bias) driving mode can be selected

- LCD driver output pins can be used as DC output ports; selectable by code option

● MFP output pin

- Output is software selectable as modulating or nonmodulating frequency

- Works as frequency output specified by Timer 1

● Two built-in 14-bit clock frequency divider circuit (divider 0 and divider 1)

● Two built-in 8-bit programmable countdown timers

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

- Timer 1: includes an auto-reload function; and one of two internal clock frequencies (FOSC or FOSC/64) can be selected or falling edge of pin RC.0 can be selected (output through MFP pin)

● Built-in 18/14-bit watchdog timer selectable for system reset

● Powerful instruction set: 118 instructions

● 8-level subroutine (include interrupt) nesting

● Up to 1 mS instruction cycle (with 4 MHz operating frequency)

● Packaged in 80-pin QFP