CHAPTER 4 I
2
C COMMUNICATIONS
User’s Manual U18438EJ2V0UD
54
4.3 Write Operation
The processing procedure, format, and operation of writing to 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 4-8. Processing Procedure of Write Operation
Remark
ST: Start condition
RST: Restart condition
SP: Stop condition
Slave ID reception
Yes
ST detected?
ID matched?
ACK
‘ — M
ACK transmission
Address reception
WD reception
SP detection
End
LCD controller/driver side (slave)
Yes
No
No
Yes
No
Slave ID transmission
Address transmission
WD transmission
End
CPU side (master)
ST generation
ACK reception
Yes
ACK transmission
SP generation
No
ACK transmission
ACK reception
Yes
No
ACK reception
Yes
No
Completed?
Yes
No
Transfer direction