TM8724
GENERAL DESCRIPTION
The TM8724 is an embedded high-performance 4-bit microcomputer with LCD driver. It contains all the necessary functions, such as 4-bit parallel processing ALU, ROM, RAM, I/O ports, timer, clock generator, dual clock operation, LCD driver, look-up table in a single chip.
BLOCK DIAGRAM
FEATURE
1. 1.5V and 3V operations and with low power dissipation.
2. Powerful instruction set (129 instructions).
Binary addition, subtraction, BCD adjust, logical operation in direct and index addressing mode.
Single-bit manipulation (set, reset, decision for branch).
Various conditional branches.
16 working registers and manipulation.
Table look-up.
LCD driver data transfer.
3. Memory capacity.
ROM capacity 1152 x 16 bits.
? RAM capacity 80 x 4 bits.
4. LCD driver output.
? 5 common outputs and 24 segment outputs (up to drive 120 LCD pixels).
? 1/1 Duty, 1/2 Duty, 1/3 Duty, 1/4 Duty or 1/5 Duty is selected by MASK option.
? 1/2 Bias or 1/3 Bias is selected by MASK option.
? Single instruction to turn off all segments and coms.
? Segment output pins (SEG1~12) could be defined as CMOS or P_open drain output type by mask option.
5. Input/output ports.
Port IOA 4 pins, muxed with SEG24~SEG27.
Port IOB 4 pins (with internal pull-low), muxed with SEG28~SEG31.
Port IOC 4 pins (with internal pull-low), muxed with SEG32~SEG35.
IOC port had built in the input signal chattering prevention circuitry.
6. 8 level subroutine nesting.
7. Interrupt function.
External factor 2 (INT pin, Port IOC).
Internal factors 2 (Pre-Divider, Timer1)
8. Built in Alarm generator.
BZB, BZ (Muxed with SEG30, SEG31).
9. One 6-bit programmable timer with programmable clock source.
10. Built-in Voltage doubler, tripler charge pump circuit.
11. Dual clock operation.
12. HALT function.
13. STOP function.
