R8C/1A Group, R8C/1B Group
16. Clock Synchronous Serial Interface
Rev.1.30
Dec 08, 2006
Page 186 of 315
REJ09B0252-0130
Figure 16.14
Sample Flowchart of Data Transmission (Clock Synchronous Communication Mode)
Start
Initialization
Read TDRE bit in SSSR register
SSSR register
TEND bit
←
0
(1)
End
TDRE = 1 ?
Write transmit data to SSTDR register
Data
transmission
continues?
Read TEND bit in SSSR register
TEND = 1 ?
No
Yes
Yes
No
No
Yes
SSER register
TE bit
←
0
(1)
(2)
(3)
(1) After reading the SSSR register and confirming
that the TDRE bit is set to 1, write the transmit
data to the SSTDR register. When the transmit
data is written to the SSTDR register, the TDRE
bit is automatically set to 0.
(2) Determine whether data transmission continues.
(3) When data transmission is completed, the TEND
bit is set to 1. Set the TEND bit to 0 and the TE bit
to 0 and complete transmit mode.
NOTE:
1. Write 0 after reading 1 to set the TEND bit to 0.