PRELIMINARY
W541C250
4-BIT MICROCONTROLLER
Publication Release Date: Feb 2002
- 1 -
Revision A2
GENERAL DESCRIPTION
The W541C250 is fully compatible with W741C250 in terms of pin assignment and IC function.. It is a
high-performance 4-bit microcontroller (
μ
C) that provides an LCD driver. The device contains a 4-bit
ALU, two 8-bit timers, a divider, a 24
×
4 LCD driver, and five 4-bit I/O ports (including 1 output port for
LED driving). There are also five interrupt sources and 8-level subroutine nesting for interrupt
applications. The W541C250 operates on low voltage and very low current and has two power
reduction modes, hold mode and stop mode, which help to minimize power dissipation.
The W541C250 is suitable for remote controllers, watches and clocks, multiple I/O products, keyboard
controllers, speech synthesis LSI controllers, and other products.
FEATURES
Operating voltage: 2.4 ~ 5.5V (LCD drive voltage: 3.0V, or 4.5V)
Single system clock
Oscillation frequency up to 4 MHz , Crystal or RC oscillator is selected by mask code option ,
High-frequency (400 KHz to 4 MHz) or low-frequency (32.768 KHz) oscillation is delected by mask
code option
Memory
2048
×
16 bit program ROM (including 2K
×
4 bit look-up table)
128
×
4 bit data RAM (including 16 working registers)
24
×
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 clock)
Five types of interrupts
Three internal interrupts (Divider 0, Timer 0, Timer 1)
Two external interrupt (Port RC and
INT
pin)
LCD driver output
24
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