TM6820

1. Low power dissipation.
2. Powerful instruction set (142 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 driver output.
`5 common outputs and 35 segment outputs (up to drive 175 LCD segments).
`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.
`Segment outputs(SEG1~35) 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 factor 2 (INT pin, Port IOC).
`Internal factor 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. Two 6-bit programmable timer with programmable clock source.
12. Watch dog timer.
13. Built-in Voltage doubler, tripler charge pump circuit.
14. 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 3.58MHz ceramic resonator, internal R or external R type oscillator by mask option.
15. HALT function.
16. STOP function.
17. Built-in control circuitry to switch the internal operating voltage in order to perform the low power consumption or provide a stable operating voltage.
18. Built-in Low Battery Detect function
19. Heavy Loading protection function

The TM6820 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, Resistance to Frequency Converter(RFC), EL panel driver, LCD driver, look-up table, watchdog timer and key matrix scanning circuitry in a signal chip.