TM8723
GENERAL DESCRIPTION
The TM8723 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, EL light, LCD driver, look-up table, watchdog timer and keyboard scanning in a signal chip.
BLOCK DIAGRAM
FEATURE
1.Low power dissipation.
2.Powerful instruction set (135 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.LCD/LED driver output.
27 LCD/LED driver outputs (up to drive 135 LCD/LED segments).
1/2 Duty, 1/3 Duty, 1/4 Duty or 1/5 Duty for both LCD/LED selected by MASK option.
1/2 Bias or 1/3 Bias for LCD selected by MASK option.
Single instruction to turn off all segments.
Mask option is used to select SEG1~12,21~35 as DC outputs/P_open drain.
4.Memory capacity.
ROM capacity1536x 16 bits.
RAM capacity96x 4 bits.
5.Input/output ports.
Port IOA4 pins.(with internal pull-low, muxed with SEG24~27)
Port IOB4 pins.(with internal pull-low, muxed with SEG28~31)
Port IOC4 pins (with internal pull-low / low-level-hold muxed with SEG32~35)
IOC port had built-in input signal chattering prevention circuitry.
6.8 level subroutine nesting.
7.Interrupt function.
External factors3(INT pin, Port IOC & KI input).
Internal factors2(Pre-Divider, Timer1).
8.Built-in EL-light driver.
ELC, ELP (Muxed with SEG28, SEG29).
9.Built in Alarm, Frequency or Melody generator.
BZB, BZ (Muxed with SEG30, SEG31).
10.Built in KEY_BOARD scanning function.
K1~K12 (Share with SEG1~SEG12).
KI1~KI4 (Muxed with SEG32~SEG35).
11.One 6-bit programmable timer with programmable clock source.
12.Watch dog timer.
13.Built-in Voltage doubler, halver, tripler charge pump circuit.
14.Dual clock operation.
15.HALT function.
16.STOP function.
