R01UH0822EJ0100 Rev.1.00
Page 692 of 1041
Jul 31, 2019
RX13T Group
23. Serial Communications Interface (SCIg, SCIh)
23.8.4
Relationship between Clock and Transmit/Receive Data
The CKPOL and CKPH bits in the SPMR can be used to set up the clock for use in transmission and reception in four
different ways. The relation between the clock signal and the transmission and reception of data is shown in
. The relation is the same for both master and slave operation.
Figure 23.57
Relation between Clock Signal and Transmit/Receive Data in Simple SPI Mode
SMISOn pin
SCKn pin
(CKPOL = 1)
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
SSn# pin
(slave)
SCKn pin
(CKPOL = 0)
(1) When CKPH = 0
SMOSIn pin
SCKn pin
(CKPOL = 1)
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
SSn# pin
(slave)
SCKn pin
(CKPOL = 0)
(2) When CKPH = 1
SMOSIn pin
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
SMISOn pin
One unit of transfer data (character or frame)