Master Mode

In Master mode, the device controls the SCK line, and as such, initiates data transfers and determines when any slaves broadcast data onto the SPI bus.

Master mode can be configured in four different modes, configured by the TXR and RXR bits:

The modes are illustrated in the following table:

Table 1. Master Mode TXR/RXR Settings
TXR = 1 TXR = 0
RXR = 1 Full Duplex mode

BMODE = 1: Transfer when RxFIFO is not full and TxFIFO is not empty

BMODE = 0: Transfer when RXFIFO is not full, TXFIFO is not empty, and the Transfer Counter is non- zero

 Receive Only mode

Transfer when RxFIFO is not full and the Transfer Counter is non-zero

Transmitted data is either the top of the FIFO or the most recently received data
RXR = 0 Transmit Only mode

BMODE = 1: Transfer when TxFIFO is not empty

BMODE = 0: Transfer when TXFIFO is not empty and the Transfer Counter is non-zero

Received data is not stored

 No Transfers
Parent topic: SPI - Serial Peripheral Interface Module