SLAU847F October 2022 – March 2026 MSPM0L1105 , MSPM0L1106 , MSPM0L1116 , MSPM0L1117 , MSPM0L1227 , MSPM0L1227-Q1 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2116 , MSPM0L2117 , MSPM0L2227 , MSPM0L2227-Q1 , MSPM0L2228 , MSPM0L2228-Q1
With the control register bits CTL0.DSS, the bit length per transfer will be defined between 4-16 bits for Controller mode and 7-16 bits for Peripheral mode.
A transfer will be triggered by writing to the TX buffer register. The data write needs to have at least the number of bits of the transfer. For example, if only a byte is written to the TX buffer, but the length of the transfer is > 8, the missing bits will be filled with 0s. On the receive path, the received data will be moved to the RXFIFO or RX buffer after the number of bits defined in the CTL0.DSS register has been received.
The RX and TX buffer shall be accessed with at least the bits covering one transfer.Clock polarity (CTL0.SPO) is used to control the clock polarity when data is not being transferred, and it is only used in theMotorola SPI frame mode.
The SPI can be configured to work in Peripheral mode with CTL1.CP bit = 0. In Peripheral mode, the clock is provided by the controller and is available to the peripheral on the CLK pins, which must be configured as inputs. The CS input signal selects/enables the peripheral's data receive path in 4-wire mode.
The SPI can be configured to work in Controller mode with CTL1.CP bit = 1. In Controller mode, the clock needs to be generated by selecting a clock source using the clock select bits. It also needs to control the CS signal depending on the selected protocol.
When setting the CTL1.PEN bit, the last bit will be used as parity to evaluate the integrity of the previous bits. The CTL1.PES bit selects the parity mode (even or odd). When detecting a fault, the interrupt flag RIS.PER is set to mark the data as invalid. Parity checking is a feature to improve the robustness of the communication.