R01UH0823EJ0100 Rev.1.00
Page 1358 of 1823
Jul 31, 2019
RX23W Group
38. Serial Peripheral Interface (RSPIa)
38.3
Operation
In this section, the serial transfer period means a period from the beginning of driving valid data to the fetching of the
final valid data.
38.3.1
Overview of RSPI Operations
The RSPI is capable of synchronous serial transfers in slave mode (SPI operation), single-master mode (SPI operation),
multi-master mode (SPI operation), slave mode (clock synchronous operation), and master mode (clock synchronous
operation). A particular mode of the RSPI can be selected by using the MSTR, MODFEN, and SPMS bits in SPCR.
lists the relationship between RSPI modes and SPCR settings, and a description of each mode.
Note 1.
This function is not supported in this mode.
Note 2.
When the SPCR.TXMD bit is 1, receiver buffer full detection, overrun error detection, and parity error detection are not performed.
Note 3.
When the SPCR2.SPPE bit is 0, parity error detection is not performed.
Note 4.
When the SPCR2.SCKASE bit is 1, overrun error detection does not proceed.
Table 38.5
Relationship between RSPI Modes and SPCR Settings and Description of Each Mode
Mode
SPI Operation
Clock Synchronous Operation
Slave
Single-Master
Multi-Master
Slave
Master
MSTR bit setting
0
1
1
0
1
MODFEN bit setting
0 or 1
0
1
0
0
SPMS bit setting
0
0
0
1
1
RSPCKA signal
Input
Output
Output/Hi-Z
Input
Output
MOSIA signal
Input
Output
Output/Hi-Z
Input
Output
MISOA signal
Output/Hi-Z
Input
Input
Output
Input
SSLA0 signal
Input
Output
Input
Hi-Z*
Hi-Z*
SSLA1, SSLA3 signals
Hi-Z*
Output
Output/Hi-Z
Hi-Z*
Hi-Z*
SSL polarity change
function
Supported
Supported
Supported
—
—
Transfer rate
Up to PCLK/8
Up to PCLK/2
Up to PCLK/2
Up to PCLK/8
Up to PCLK/2
Clock source
RSPCK input
On-chip baud rate
generator
On-chip baud rate
generator
RSPCK input
On-chip baud rate
generator
Clock polarity
Two
Clock phase
Two
Two
Two
One (CPHA = 1)
Two
First transfer bit
MSB/LSB
Transfer data length
8 to 16, 20, 24, 32 bits
Burst transfer
Possible
(CPHA = 1)
Possible
(CPHA = 0,1)
Possible
(CPHA = 0,1)
—
—
RSPCK delay control
Not supported
Supported
Supported
Not supported
Supported
SSL negation delay control
Not supported
Supported
Supported
Not supported
Supported
Next-access delay control
Not supported
Supported
Supported
Not supported
Supported
Transfer activation method SSL input active
or RSPCK
oscillation
Transmit buffer is
written to when a
transmit buffer empty
interrupt request is
generated or the
SPTEF flag is 1
Transmit buffer is
written to when a
transmit buffer empty
interrupt request is
generated or the
SPTEF flag is 1
RSPCK oscillation
Transmit buffer is
written to when a
transmit buffer empty
interrupt request is
generated or the
SPTEF flag is 1
Sequence control
Not supported
Supported
Supported
Not supported
Supported
Transmit buffer empty
detection
Supported
Receive buffer full
detection
Supported*
Overrun error detection
Supported*
Supported*
Supported*
Supported*
Parity error detection
Supported*
Mode fault error detection
Supported
(MODFEN = 1)
Not supported
Supported
Not supported
Not supported