CHAPTER 4 I
2
C COMMUNICATIONS
User’s Manual U18438EJ2V0UD
57
Slave ID reception
Yes
ST detected?
No
ID matched?
ACK
‘ — M
ACK transmission
Address reception
RST detected?
Slave ID reception
ID matched?
RD transmission
ACK reception
SP detection
End
Yes
LCD controller/driver side (slave)
No
No
Yes
Yes
No
No
Yes
No
Slave ID transmission
Address transmission
Slave ID transmission
RD reception
ACK transmission
End
Yes
CPU side (master)
Yes
No
ST generation
ACK reception
Yes
RST generation
ACK transmission
ACK reception
Yes
SP generation
No
No
Transfer direction
ACK reception
Yes
No
ACK transmission
Slave ID reception
Yes
ST detected?
No
ID matched?
ACK
‘ — M
ACK transmission
Address reception
RST detected?
Slave ID reception
ID matched?
RD transmission
ACK reception
SP detection
End
Yes
LCD controller/driver side (slave)
No
No
Yes
Yes
No
No
Yes
No
Slave ID transmission
Address transmission
Slave ID transmission
RD reception
ACK transmission
End
Yes
CPU side (master)
Yes
No
ST generation
ACK reception
Yes
RST generation
ACK transmission
ACK reception
Yes
SP generation
No
No
Transfer direction
ACK reception
Yes
No
ACK transmission
4.4 Read Operation
The processing procedure, format, and operation of reading the LCD controller/driver via the I
2
C bus interface are
explained below.
The LCD controller/driver register to be accessed can be specified with the slave ID and address (see Figure 3-3).
(1) Processing procedure
Figure 4-11. Processing procedure of Read Operation
Remark
ST: Start condition
RST: Restart condition
SP: Stop condition