BU9797FUV Datasheet, PDF (8/28 Pages) Rohm – Integrated Buffer AMP for LCD Driving

BU9797FUV MAX 144 segments (SEG36×COM4)
Datasheet
Read Display Data and Transfer Method
If the LSB of the slave address is “1”, it will be set read mode.
The display data and command register value can be read during read mode.
The read mode sequence is shown below.
Slave address
Com ma nd
S 0111110 0 A 1 1101000
Com ma nd
Slave address
A 1 0000000 A S 0111110 1 A
Data A …...
R/W(Write Mode)
Set ICSET [P2]=0
ADSET command
R/W(Read Mode)
Data N A P
During read mode, the display data can be read from the DDRAM through the SDA line.
The data will output with SCL input synchronous.
First it has to set address by write mode ADSET command to read display data.
If DDRAM address does not specify before DDRAM read, the read address will be start from the current
DDRAM address.
Address will be increment +2 addresses by 8bit data output automatically.
Master side should be output ACK output by each 8bit data output.
It will be able to keep read mode and address increment by ACK from master side.
If there is no ACK response, SDA output status will be released, please transmit “STOP condition”.
Read mode will be stopped by “STOP condition” transfer.
Address will be set 00h automatically after 23h. (It does not increment to 24h or 25h address)
An example of the display data read sequence is shown below.
S
SDA
SCL
Slave Address (read)
P
A D7 D6 D5 D4 D3 D2 D1 D0 A D7 D6 D5 D4 D3 D2 D1 D0 NA
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111ï½¥15ï½¥001
8/25
TSZ02201-0P4P0D300820-1-2
5.Aug.2014 Rev.001