W742C814
1. GENERAL DESCRIPTION
The W742C814 is a high-performance 4-bit micro-controller (µC) that provides an LCD driver. The
device contains a 4-bit ALU, two 8-bit timers, two dividers (for two oscillators) in dual-clock operation,
a 32 × 4 LCD driver, five 4-bit I/O ports (including 1 output port for LED driving), and one channel
DTMF generator. There are also five interrupt sources and 8-levels subroutine nesting for call
subroutine or interrupt applications. The W742C814 operates on very low current and has two power
reduction modes, that is the dual-clock slow operation and STOP mode, which help to minimize power
dissipation.
2. FEATURES
• Operating voltage: 2.4V - 5.5V
• Dual-clock operation mode (Connect to 32768 Hz crystal only)
Fslow oscillator: 32768 Hz OSC
Ffast oscillator: PLL (Phase Lock Loop) output enable
• Memory
− 4096 x 16 bits program ROM (including 16K x 4 bit look-up table)
− 1024 x 4 bits data RAM (including 16 nibbles x 16 pages working registers)
− 32 x 4 LCD data RAM
• 20 input/output pins
− Port for input only: 1 ports/4 pins (RC)
− Input/output ports: 3 ports/12 pins (RA, RB & RD)
− High sink current output port for LED driving: 1 port /4 pins (RE)
• Power-down mode
− Hold function: no operation (excluding Fslow and Fosc oscillator)
− Stop function: no operation (Fslow and Fosc oscillator are stopped)
− Dual-clock slow operation mode: system is operated by 32768 Hz (FOSC = Fslow and Ffast
stopped)
• Five types of interrupts
− Four internal interrupts (Divider0, Divider1, Timer 0, Timer 1)
− One external interrupts (RC Port)
• LCD driver output
− 32 segments x 4 commons
− 1/4 duty 1/3 bias driving mode
• MFP output pin
− Output is software selectable as modulating or non-modulating frequency
− Works as frequency output specified by Timer 1
• DTMF output pin (PLL should be enable in this function)
Publication Release Date: February 12, 2003
-3-
Revision A2