R01UH0823EJ0100 Rev.1.00
Page 1074 of 1823
Jul 31, 2019
RX23W Group
33. Serial Communications Interface (SCIg, SCIh)
33.8.4
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 33.58
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)