8.3.8.10 Local Loopback Test Mode

Local Loopback mode connects the output of the transmitter directly to the input of the receiver, as shown in the figure below. The MISO pin has no effect on the receiver and the MOSI pin is driven as in Normal mode.

The MOSI, SPCK and NPCSx are normally transmitted unless the PIO is configured to drive logical values to prevent the SPI external target device from starting.

Local Loopback mode and allows a quick and easy verification of the transmitter and receiver logic.

Local Loopback mode is enabled when FLEX_SPI_MR.LLB=1, FLEX_SPI_MR.MASTER=1 and the FLEX_MR.OPMODE=2.