TXZ Family
Serial Peripheral Interface
2019-02-28
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Rev. 3.0
(3) LSB first transfer (31-bit data with parity; frame length is 32-bit)
Figure 3.8 shows a 31-bit data length transmit/receive operation (with a parity bit, LSB first, 31-bit data
length).
In the transmission, data D30 through D0 in the transmit FIFO is sorted bit by bit and the data is copied to
bit 31 through bit 1 in the shift register. At the same time, a parity is calculated using data D30 through D0.
The result is stored in the D0 in the shift register.
Consequently, transmit data in the shift register and a parity data are sequentially transferred from D31 to
D0 in the shift register on serial clock.
In the reception, receive data is stored in the D0 of the shift register. Shift operation repeats on serial clock.
If the shift register stores 31-bit reception data, only data excluding a parity bit is copied to the receive
FIFO.
Figure 3.8 LSB first (31-bit data with parity)
[TSPIxDR]
(Data register)
[TSPIxDR]
(Data register)