W541C20X

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1. GENERAL DESCRIPTION

The W541C20X is fully compatible with W741C20X in the terms of pin assignment and IC functon. It is

a high-performance 4-bit microcontroller (

µC) that operates on very low current. The device contains a

4-bit ALU, two 8-bit timers, a divider, a serial port, and five 4-bit I/O ports (including 3 output ports for

LED driving). There are also seven interrupt sources and 8-level subroutine nesting for interrupt

applications. The W541C20X has two power reduction modes, hold mode and stop mode, which help

to minimize power dissipation.

The W541C20X is suitable for remote controllers, toy controllers, keyboard controllers, speech

synthesis LSI controllers, and other products.

2. FEATURES

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Operating voltage: 2.4V to 5.5V

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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

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Memory

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

−128 x 4 bit data RAM (including 16 working registers)

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21 input/output pins

−Input/output ports: 4 ports/16 pins

− Serial input/output port: 1 port /4 pins (high sink current for LED driving)

− MFP output pin: 1 pin (MFP)

−Do not be floating when it is as input or output open-drain (NMOS type).

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Power-down mode

−Hold function: no operation (except for oscillator)

−Stop function: no operation (including oscillator)

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Seven types of interrupts

−Five internal interrupts (Divider 0, Timer 0, Timer 1, and Serial I/O)

T

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MFP output pin

−Output is software selectable as modulating or nonmodulating frequency

−Works as frequency output specified by Timer 1

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Built-in 14-bit clock frequency divider circuit