R01UH0823EJ0100 Rev.1.00
Page 1340 of 1823
Jul 31, 2019
RX23W Group
38. Serial Peripheral Interface (RSPIa)
4. The RSPI internal sequencer has entered the idle state (status in which operations up to the next-access delay have
finished)
Slave mode
The SPCR.SPE bit is 0 (disables the RSPI function)
MODF Flag (Mode Fault Error Flag)
Indicates the occurrence of a mode fault error.
[Setting condition]
Multi-master mode
When the input level of the SSLAi pin changes to the active level while the SPCR.MSTR bit is 1 (master mode) and
the SPCR.MODFEN bit is 1 (mode fault error detection is enabled), the RSPI detects a mode fault error
Slave mode
When the SSLAi pin is negated before the RSPCK cycle necessary for data transfer ends while the SPCR.MSTR bit
is 0 (slave mode) and the SPCR.MODFEN bit is 1 (mode fault error detection is enabled), the RSPI detects a mode
fault error
The active level of the SSLAi signal is determined by the SSLP.SSLiP bit (SSLi signal polarity setting bit).
[Clearing condition]
When SPSR is read while the MODF flag is 1, and then 0 is written to the MODF flag
Indicates the occurrence of a parity error.
[Setting condition]
When a serial transfer ends while the SPCR.TXMD bit is 0 and the SPCR2.SPPE bit is 1, the RSPI detects a parity
error
[Clearing condition]
When SPSR is read while the PERF flag is 1, and then 0 is written to the PERF flag
SPTEF Flag (Transmit Buffer Empty Flag)
Indicates whether the transmit buffer (SPTX) in the RSPI data register has valid data.
[Setting condition]
When the SPCR.SPE bit is 0 (disables the RSPI function)
When data is transferred from the transmit buffer to the shift register
[Clearing condition]
When the number of frames of transmit data specified by the SPDCR.SPFC[1:0] bits is written to the SPDR register
The SPDR register can be set only when the SPTEF flag is 1. The data in the transmit buffer is not updated when the
SPDR register is set while the SPTEF flag is 0.
SPRF Flag (Receive Buffer Full Flag)
Indicates whether the receive buffer (SPRX) in the RSPI data register has valid data.
[Setting condition]
When the number of frames of receive data specified by the SPDCR.SPFC[1:0] bits is transferred from shift register
to the receive buffer (SPRX) while the SPCR.TXMD bit is 0 (full duplex) and the SPRF flag is 0.
Note that the SPRF flag does not become 1 when the OVRF flag is 1.