Standard ICs
LCD controller driver for dot matrix
displays
BU97701 / BU97702
The BU97701 and BU97702 are controller drivers used in dot matrix liquid crystal displays that display English-lan-
guage characters, Japanese kana characters, and symbols. These products can be controlled by a 4-bit or an 8-bit
MPU. All of the functions necessary to drive dot matrix displays are contained on a single chip, enabling liquid crystal
displays to be configured with a small number of chips. These products are available in QFP-T80 (BU97701) and
SQFP-T80 (BU97702) packages.
•
Applicationsdisplay systems for character displays
Liquid crystal
•
Features
1) Can accommodate 5
×
7 and 5
×
10 dot matrix
LCDs.
2) Equipped with an internal display data RAM of 80
×
8 bits; an expansion driver (BU9706KS) can be used
to expand the display up to 80 characters.
3) Internal display data ROM of 12,000 bits
4) Diverse variety of functions includes display clear,
cursor home, display on / off, display character blink,
display shift, and others.
•
Absolute maximum ratings (Ta = 25°C)
Parameter
Power supply voltage
Power
dissipation
BU97701
BU97702
Symbol
V
DD
Pd
Topr
Tstg
Limits
– 0.3 ~ + 7.0
900
∗
1
800
∗
2
– 20 ~ + 75
– 55 ~ + 125
Unit
V
mW
°C
°C
Operating temperature
Storage temperature
∗
1 Reduced by 9.0mW for each increase in Ta of 1°C over 25°C (QFP-T80).
∗
2 Reduced by 8.0mW for each increase in Ta of 1°C over 25°C (SQFP-T80).
•
Recommended operating conditions (Ta = 25°C)
Parameter
Power supply voltage
Symbol
V
DD
Min.
4.5
Typ.
—
Max.
5.5
Unit
V
•
Model names
Model Number
BU97701-00 / BU97702-00
BU97701-01 / BU97702-01
BU97701-02 / BU97702-02
Built-in font
ROM Ver.00
ROM Ver.01
ROM Ver.02
1
Standard ICs
BU97701 / BU97702
•
Pin descriptions
Pin No.
Pin name
Function
Selects the register used to read / write instructions and data.
If RS = 0 and R / W = 0: Instruction register
If RS = 0 and R / W = 1: Busy flag and address counter
If RS = 1: Data register
Signal that selects the read or write operation.
This sends and receives data between the BU97701-00 (BU97702) and host
computer.
R / W = 0: Write R / W = 1: Read
Signal which enables reading / writing.
Highest four bits of 3-state bi-directional bus.
These send and receive data between the BU97701 (BU97702) and host
MPU. These are not used with 4-bit operation.
Lowest four bits of 3-state bi-directional bus.
These send and receive data between the BU97701 (BU97702) and host
MPU.
Signal output which latches the serial data of the external segment driver.
Signal output which shifts the serial data of the external segment driver.
AC signal output of the LCD drive waveform.
Outputs the data corresponding to the character pattern to an external
segment register.
0: OFF data 1: ON data
Commons: these are common drive signals. At 1 / 8 duty, COM9 to COM16
are de-selected waveforms. At 1 / 11 duty, COM12 to COM16 are de-selected
waveforms.
36 (34)
RS
37 (35)
R/W
38 (36)
39 ~ 42
(37 ~ 40)
43 ~ 46
(41 ~ 44)
31 (29)
32 (30)
34 (32)
35 (33)
47 ~ 62
(45 ~ 60)
22 ~ 1
(20 ~ 1)
80 ~ 63
(80 ~ 61)
30 (28)
26 ~ 29
(24 ~ 27)
33, 23
(31, 21)
24, 25
(22, 23)
E
DB
0
~ DB
3
DB
4
~ DB
7
LOAD
CP
DF
D
COM
1
~ COM
16
SEG
1
~ SEG
40
V
5
V
1
~ V
4
V
DD
, V
SS
Segments: segment drive signals.
LCD power supply
LCD power supply for external driver.
These must satisfy
the following relationship:
V
DD
V
1
V
2
V
3
V
4
V
5
V
SS
Power supply pins;
V
DD
= 5.0
±
10%,
V
SS
= 0V
When the internal clock is operating, the resistance is connected to these pins.
When an external clock is operating, the clock is input to OSC
1
. (OSC
2
is
open.)
OSC
1
, OSC
2
∗
The 97702 pin numbers are indicated within parentheses.
4
Embedded System
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