ST7066U
!"Pin Function
Name
Number I/O Interfaced with
Function
Select registers.
0: Instruction register (for write) Busy flag:
address counter (for read)
RS
1
I
MPU
1: Data register (for write and read)
Select read or write.
0: Write
R/W
E
1
1
I
I
MPU
MPU
1: Read
Starts data read/write.
Four high order bi-directional tristate data bus
pins. Used for data transfer and receive
between the MPU and the ST7066U. DB7 can
DB4 to DB7
DB0 to DB3
4
4
I/O
I/O
MPU
be used as a busy flag.
Four low order bi-directional tristate data bus
pins. Used for data transfer and receive
between the MPU and the ST7066U.
MPU
These pins are not used during 4-bit operation.
Clock to latch serial data D sent to the
extension driver
CL1
CL2
M
1
1
1
O
O
O
Extension driver
Extension driver Clock to shift serial data D
Switch signal for converting the liquid crystal
drive waveform to AC
Character pattern data corresponding to each
segment signal
Extension driver
Extension driver
D
1
O
Common signals that are not used are changed
to non-selection waveform. COM9 to COM16
are non-selection waveforms at 1/8 duty factor
and COM12 to COM16 are non-selection
COM1 to
COM16
O
16
LCD
waveforms at 1/11 duty factor.
Segment signals
SEG1 to
SEG40
40
O
LCD
Power supply for LCD drive
V1 to V5
5
2
-
-
Power supply
Power supply
VCC - V5 = 10 V (Max)
VCC , GND
V
CC : 2.7V to 5.5V, GND: 0V
When crystal oscillation is performed, a resistor
must be connected externally. When the pin
input is an external clock, it must be input to OSC1.
Oscillation
resistor clock
OSC1, OSC2
2
Note:
1. Vcc>=V1>=V2>=V3>=V4>=V5 must be maintained
2. Two clock options:
R=91KΩ(Vcc=5V)
R=75KΩ(Vcc=3V)
OSC1
OSC2
OSC1
OSC2
R
Clock
input
V2.0
2001/03/01
8/42
POWERTIP [ POWERTIP TECHNOLOGY ]
