
R8C/38T-A Group
21. Clock Synchronous Serial Interface
Under development Preliminary document
Specifications in this document are tentative and subject to change.
R01UH0241EJ0010 Rev.0.10
Page 481 of 730
Aug 05, 2011
21.3.2
Clock Synchronous Communication Mode
21.3.2.1
Initialization in Clock Synchronous Communication Mode
reception, set the TE_NAKIE bit in the SIER register to 0 (transmission disabled) and the RE_ STIE bit to 0
(reception disabled) for initialization.
To change the communication mode (select clock synchronous communication mode by the mode select MS bit
in the SIMR2 register) or the communication format, set the TE_NAKIE bit to 0 and the RE_STIE bit to 0
before making the change.
Even if the RE_STIE bit is set to 0, the contents of bits RDRF and ORER_AL in the SISR register and the
SIRDR register are retained.
Figure 21.6
Initialization in Clock Synchronous Communication Mode
Start
SIMR2 register
MS bit
0
SICR1 register
Set bits CKS0 to CKS2
Set RCVD bit
SISR register
ORER_AL bit
0 (1)
SIER register
RE_STIE bit
1 (receive)
TE_NAKIE bit
1 (transmit)
Set bits RIE, TEIE, and TIE
End
Note:
1. To set the ORER_AL bit to 0, write 0 after reading it as 1.
SIER register
RE_STIE bit
0
TE_NAKIE bit
0
SIMR2 register
SCKS bit
1
Set SOOS bit
SICR1 register
Set MST bit
SIMR1 register
CPHS bit
0
CPOS_WAIT bit
0
Set MLS bit
Reception disabled
Transmission disabled
SSBR register
Set bits BS0 to BS3
SSU data transfer length setting
Mode selected (clock synchronous communication mode)
Clock phase selected (data change at odd edge)
Clock state selected (high when clock stops)
MSB/LSB first selected
Master/slave mode selected
SSCK pin selected (serial clock pin)
SSCK pin open-drain output selected
Clock period setting
Receive disable bit setting
Overrun error flag cleared
Transmission/reception enable setting
Interrupt enable setting