General Description

The APU429 is an embedded high performance 4-bit micro-computer with an on-chip LCD driver. It contains all the necessary functions in a single chip: 4-bit parallel processing ALU, ROM, RAM, I/O ports, timer, clock generator, dual clock, RFC, EL-light, LCD driver, look-up table, watchdog timer and keyboard scanning. The instruction set includes not only 4-bit operation and manipulation instructions but also various conditional branch instructions and LCD driver data transfer instructions which are powerful and easy to use.

Features

? Low power and low voltage operation

? Powerful instruction set (150 instructions)

? Memory capacity

- Instruction ROM capacity 4096 x 16 bits

- Index ROM capacity 256 x 8 bits

- Internal RAM capacity 384 or 256 x 4 bits

? Input/Output ports of up to 20 pins

? 8-level subroutine nesting

? Built-in LCD driver, 8 x 42 = 336 segments

? Built-in EL driver, frequency or melody generator

? Built-in Resistance-to-Frequency Converter

? Built-in 2-channel 6/8-bit PWM output

? Built-in key strobe function

(Shared with segment pin)

? Built-in voltage doubler, halver, tripler quadrupler charge pump circuit

? Two 6-bit programmable timers with programmable clock source

? Watchdog timer

? 4 external & 3 internal interrupt resources

- External: INT, RFC, IOA/IOC/S port, keystrobe

- Internal: TM1, TM2, Predivider

? Dual clock operation

? HALT and STOP function