GENERAL DESCRIPTIONThe TM87P18M is a One Time PROM embedded high-performance 4-bit
microcontroller with LCD driver. It contains all the following
functions on 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, watchdog
timer and key matrix scanning circuitry.
FEATURES1.Powerful instruction set (173 instructions).
Binary addition, subtraction, BCD adjusts, 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.
2.Memory capacity.
ROM capacity 4096 x 16 bits
Data RAM capacity 512 x 4 bits.
3.Input/output ports.
Port IOA 4 pins (with internal pull-low), muxed with SEG24~SEG27.
Port IOB 4 pins (with internal pull-low), muxed with SEG28~SEG30, DC31.
Port IOC 4 pins (with internal pull-low, low-level-hold, chattering
prevention clock).
Port IOD 4 pins (with internal pull-low, chattering prevention clock).
4.8-level subroutine nesting.
5.Interrupt function.
External factor 4 (INT pin, Port IOC, IOD & KI input).
Internal factor 4 (Pre-Divider, Timer1, Timer2, RFC).
6.Built-in Alarm, Frequency or Melody generator.
7.BZB, BZ (Mux with IOB3/SEG30, IOB4/DC31).
8.Built-in R to F Converter circuit.
CX, RR, RT, RH (Mux with IOA1~IOA4/SEG24~27).
9.Built-in KEY_BOARD scanning function.
K1~K16 (Share with SEG1~SEG16).
KI1~KI4 (Mux with IOC1~IOC4).
10.Two 6-bit programmable timers with programmable clock source.
11.Watch dog timer.
12.LCD driver output.
32 LCD/LED driver outputs (up to 256 LCD segment drivable).
1/2 ~ 1/8 Duty for LCD/LED.
1/2 Bias or 1/3 Bias for LCD/LED selected by option.
Single instruction to turn off all segments.
Option is used to select COM5~8, DC9/OD9, SEG17~ SEG23,
DC31/OD31,SEG40, SEG41,as DC outputs/P_open drain.
32 LCD address.
13.Built-in Voltage doubler, halver charge pump circuit.
14.Dual clock operation, and X’tal type slow oscillation, and fast
oscillation can set 3.58 MHz ceramic resonator, internal R or
external R by switch option.
15.HALT function.
16.STOP function.
17.ROM code protect fuse.
APPLICATIONTimer / Calendar / Calculator