What to pay attention to when operating the M451 full-duplex SPI?

[a_ziliu]

The NuMicro® M451 SPI supports full-duplex mode, which transmits (receives) data as well as receives (transmits) data, thus improving the SPI transmission efficiency. Therefore, before receiving data, user must first empty the SPI RX FIFO to avoid receiving unexpected data. In the code, user must first call SPI_ClearRxFIFO (SPIn), and then receive SPI RX data.
The reference code is located in the following path: M451SeriesBSP_v3.01.001\SampleCode\NuEdu\
Smpl_Basic01_SPI_Flash_w_PDMA
In the sample code of the NuEdu-Basic01_SPI_Flash_w_PDMA.c, user first clears the RX FIFO data in the 330th row and then triggers the RX receive data, as shown below.