GENERAL DESCRIPTIONThe TM8722 is an embedded high-performance 4-bit microcomputer with LCD/LED
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, Resistance
to Frequency Converter(RFC), EL panel driver, LCD driver, look-up table, watchdog
timer and key matrix scanning circuitry in a signal chip.
FEATURES1. Low power dissipation.
2. Powerful instruction set (143 instructions).
Binary addition, subtraction, BCD adjust, logical operation in direct and
index addressing mode.
Single-bit manipulation (set, reset, decision for branch).
Various conditional branch.
16 working registers and manipulation.
Table look-up.
LCD driver data transfer.
3. Memory capacity.
ROM capacity 2048 x 16 bits.
RAM capacity 128 x 4 bits.
4. LCD/LED driver output.
5 common outputs and 35 segment outputs (up to drive 175 LCD/LED
segments).
1/2 Duty, 1/3 Duty, 1/4 Duty or 1/5 Duty for both LCD/LED drivers is
selected by mask option.
1/2 Bias or 1/3 Bias for LCD driver is selected by mask option.
Single instruction to turn off all segments.
All segment outputs could be defined as CMOS or P_open drain output
type by mask option.
5. Input/output ports.
Port IOA 4 pins (with internal pull-low), muxed with SEG24~27.
Port IOB 4 pins (with internal pull-low), muxed with SEG28~31.
Port IOC 4 pins (with internal pull-low/low-level-hold), muxed
with SEG32~35. IOC port had built in the input signal
chattering prevention circuitry.
6. 8 level subroutine nesting.
7. Interrupt function.
External factors 3 (INT pin, Port IOC & KI input).
Internal factors 4 (Pre-Divider, Timer1, Timer2 & RFC).
8. Built-in EL panel driver.
ELC, ELP (Muxed with SEG28, SEG29).
9. Built in Alarm, clock or single tone melody generator.
BZB, BZ (Muxed with SEG30, SEG31).
10. Built-in R to F Converter circuit.
CX, RR, RT, RH (Muxed with SEG24~SEG27).
11. Built in key matrix scanning function.
K1~K16 (Shared with SEG1~SEG16).
KI1~KI4 (Muxed with SEG32~SEG35).
12. Two 6-bit programmable timer with programmable clock source.
13. Watch dog timer.
14. Built-in Voltage doubler, halver, tripler charge pump circuit.
15. Dual clock operation
slow clock oscillation can be defined as X’tal or external RC type
oscillator by mask option.
fast clock oscillation can be defined as internal R or external R type
oscillator by mask option.
16. HALT function.
17. STOP function.