The W541E20X is fully compatible with W741E20X in terms of pin assignment and IC function. It is a high-performance 4-bit microcontroller (C) that provides an flash EEPROM for the program memory. 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 port for LED driving). There are also seven interrupt sources and 8-level subroutine nesting for interrupt applications. The W541E20X has two power reduction modes, hold mode and stop mode, which help to minimize power dissipation. The W541E20X is suitable for end product manufacturer engineering testing and earlier samples before mass production.