1.0 General Description

The ASM4112CB is very low cost voice synthesizer with 4-bit microprocessor. It has various features including 4-bit ALU, ROM, RAM, I/O ports, timers, clock generator, watchdog timer(WDT), voice synthesizer, etc. It consists of 22 instructions in the device. With CMOS technology and halt function can minimize power dissipation. Its architecture is similar to RISC, with two stages of instruction pipeline. It allows all instructions to be executed in a single cycle, except for program branches and data table read instructions (which need two instruction cycles).



1.1 Feature

 Single power supply can operate from 2.4V through 5V

 Internal Program ROM: 4K x 10-bit

 1 sets of 17-bit DPR can access up to 128K x 10 bits data memory space

 Data Registers:

   • 96 x 4-bit data RAM (00-1Fh plus 40h-7Fh)

   • Unbanked special function registers (SFR) range: 20h-3Fh  I/O Ports:

   • PRA: 4-bit I/O Port A (2Bh)

   • PRB: 4-bit Output Port B (2Dh)

   • PRC: 4-bit Input Port C (2Fh)

 On-chip clock generator: Resistive Clock Drive(RM)

 Timer: 1

   • Timer0: a 9-bit auto-reload timer/counter

 Stack: 2-level subroutine nesting

 HALT and Release from HALT function to reduce power consumption

 Watch Dog Timer (WDT)

 Instruction: 1-cycle instruction except for table read and program branches which are 2-cycles

 Number of instruction: 22

 The Voice function can be implemented by microprocessor instruction

   • One 8-bit COUT output for ASMXXXXX