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