NJU6625 New Japan Radio Co.,Ltd, NJU6625 Datasheet - Page 26

• Manufacturer Part Number: NJU6625
• Description: Nju6625 12character 1-line Dot Matrix Lcd Controller Driver With Smooth Scroll Function
• Manufacturer: New Japan Radio Co.,Ltd

NJU6625
(5) Interface with MPU
COMMK
- 26 -
based on 16-bit per word.
terminal to the rising edge. The inputs data and latched at rising edge of shift clock (SCL) and the first 16-bit
data are fetched into the NJU6625 at the rising edge of chip select (CSb). The data over than 16 bits are
ignored. If the input data are less than 16 bits, they are ignored at the rising edge of "CSb". Therefore, just 16
bits data should be input for the correct communication. In case of RAM data input, the RAM address is
changed automatically as increment or decrement.
data read out instruction are input. After these 8 -bit instruction is input, this serial data input terminal is
changed to the output terminal at the 8th falling edge of SCL clock.
(4-3) Relation between oscillation frequency and LCD frame frequency
CSb
SCL
DATA
The instructions and data are communicated with the serial port which is a clock synchronization type
The NJU6625 can be controlled by the serial data as shown below.
The serial interface circuit operates in CSb=L.
A communication unit consists of 16-bit data. The communication period is from the falling edge of CSb
The data to input is MSB first. Although the output data is just only key scan, data bits D
The electrical short between the NJU6625 and external circuit must be prevented in the application.
available without any external components.
As the NJU6625 incorporate oscillation capacitor and resistor for CR oscillation, 145kHz oscillation is
The LCD frame frequency example mentioned below is based on 145kHz oscillation.(1clock =6.90us)
V
V
LCD
V
V
V
SS
1
2
4
224 clock
Icon
1
1 frame = 6.90(us) x 224 x 8 = 12.36(ms)
Frame frequency = 1 / 12.36(ms) = 79.50(Hz)
Keyscan time = 220.70(us)
Prelimina ry
2
1 frame
3
････
7
Key
Icon
1
2
3
1 frame
････
7
key
Icon
8
Is Keyscan wave form
to D
1
15
2
in the key
Ver.2008-03-21