GENERAL DESCRIPTION

The TM8761 is an embedded high-performance 4-bit microcomputer with LCD driver. It contains all the of the following functions in a single chip: 4-bit parallel processing ALU, ROM, RAM, I/O ports, timer, clock generator, dual clock operation, Resistance to Frequency Converter (RFC), LCD driver, look-up table. 

BLOCK DIAGRAM

FUNCTION

1. Powerful instruction set (137 instructions)

• Binary addition, subtraction, BCD adjustment, logical operation in direct and index addressing mode.

• Single-bit manipulation (set, reset, decision for branch).

• Various conditional branches.

• 16 working registers and manipulation.

• Look-up table.

• LCD driver data transfer.

2. Memory capacity

• ROM capacity             1024  x  16 bits.

• RAM capacity                 64  x    4 bits.

3.  Input/output ports

• Port IOA4             1 pin (with internal pull-low).

  IOA4 port has built-in input signal chattering prevention circuitry.

• Port IOC               4 pins (with internal pull-low, low-level-hold).

• Port IOB3, 4         2 pins (with internal pull-low), & mask option with BZB, BZ.

4.  8-level subroutine nesting.

5.  Interrupt function

• External factor            1     (Pin IOA4 port).

• Internal factors           3     (Pre-Divider, Timer2 & RFC).

6.  Built-in Alarm, clock or single tone melody generator (BZB, BZ), & mask option with IOB3, 4.

7.  Built-in R to F Converter circuit

• CX, RR, RT.

8.  One 6-bit programmable timer (Timer 2) with programmable clock source.

9. LCD driver output

9 LCD driver outputs (Up to drive 36 LCD segments) .

• 1/4 Duty and 1/2 Bias for LCD display.

• Single instruction to turn off all segments.

• 9 DC/Open Drain outputs for LED mask option.

• 16 LCD Address.

10.  Built-in Voltage double charge pump circuit.

11.  Clock oscillation can be defined as X’tal, external-R or internal-R 2 type oscillators by mask option.

12.  HALT function.

13.  STOP function.