TM8704
tenx technology
GENERAL DESCRIPTION
The TM8704 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, LCD driver and look-up table in a
signal chip.
FEATURE
1. 1.5V operation only and with low power dissipation.
2. Powerful instruction set (129 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
RAM capacity
1152
80
x 16 bits.
x 4 bits.
4 Bit Microcontroller
4. LCD driver output.
5 common outputs and 24 segment outputs (up to drive 120 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 output pins (SEG1~12) could be defined as CMOS or P_open drain output
type by mask option.
5. Input/output ports.
Port IOA
4 pins, muxed with SEG24~SEG27.
Port IOB
4 pins(with internal pull-low), muxed with SEG28~SEG31.
Port IOC
4 pins(with internal pull-low), muxed with SEG32~SEG35.
IOC port had built in the input signal chattering prevention circuitry.
6. 8 level subroutine nesting.
7. Interrupt function.
External factor 2
Internal factors 2
(INT pin, Port IOC).
(Pre-Divider, Timer1).
8. Built-in Diode for Solar Cell power regulation.
9. Built in Alarm generator.
tenx technology, inc.
Ver 1.0 03/12/01
TM8704
BZB, BZ (Muxed with SEG30,SEG31).
10. One 6-bit programmable timer with programmable clock source.
11. Built-in Voltage doubler, tripler charge pump circuit.
12. Dual clock operation.
13. HALT function.
14. STOP function.
APPLICATION
Timer / Calendar / Calculator
BLOCK DIAGRAM
B1-4
BZB,BZ
B-PORT
A-PORT
ALARM
4 BITS DATA BUS
INDEX ROM
256(9-N) X 8 BITS
DATA RAM
80 X 4 BITS
C-PORT
SEGMENT PLA
A1-4
C1-4
COM1-5
SEG1-12,24-35
LCD DRIVER
VDD1-3
ALU
PRE-DIVIDER
6 BITS PRESET
TIMER 1
CONTROL
CIRCUIT
RESET
INT
8 LEVELS
STACK
11 BITS PROGRAM
COUNTER
INSTRUCTION
DECODER
MASK ROM
128N X 16 BITS
N:1->9
OSCILLATOR
CUP1,2 XTIN,OUT
2
tenx technology, inc.
Ver1.0 03/12/01
TM8704
PIN DESCRIPTION
Name
VDD1,2,3
RESET
INT
I/O
P
I
I
Description
LCD supply voltage, and positive supply voltage.
Input pin for external reset request signal, built-in internal pull-down resistor.
Input pin for external interrupt request signal.
. Falling edge or rising edge triggered is defined by mask option.
. Internal pull-down or pull-up resistor is defined by mask option.
Test signal input pin.
Switching pins for supply the LCD driving voltage to the VDD1,2,3 pins.
. Connect the CUP1 and CUP2 pins with non-polarized electrolytic capacitor when chip
operated in 1/2 or 1/3 bias mode.
. In no BIAS mode, leave these pins opened.
Time base counter frequency (clock specified. LCD alternating frequency. Alarm signal
frequency) or system clock oscillation.
. 32KHz Crystal oscillator or External RC for SLOW ONLY or DUAL by mask option.
. In FAST ONLY mode option, connect an external resistor could compose a RC
oscillator.
Output pins for driving the common pins of the LCD panel.
Output pins for driving the LCD panel segment.
Input / Output port A.(muxed with SEG24~27)
Input / Output port B.(muxed with SEG28~30)
Input / Output port C. (muxed with SEG32~35)
Output port for alarm generator
Negative supply voltage.
TEST
CUP1,2
O
XIN
XOUT
I
O
COM1~5
SEG1-12,24-
35
IOA1-4
IOB1-4
IOC1-4
BZB/BZ
GND
O
O
I/O
I/O
I/O
O
P
5
tenx technology, inc.
Ver1.0 03/12/01
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