Other Parts Discussed in Thread: SYSBIOS
AM4379 McSPI not working in; 4 wire, Single Channel, Master Mode during read operation. All write operations work correctly. I am communicating to a Microchip KSZ9477 7-port Ethernet switch over SPI. The Sitara is in master mode and the switch is a slave. I have verified with a Scope that the Sitara transmits the correct data and that the KSZ device responds correctly. However, the Sitara always reads zero at the Rx register. I have tried an interrupt driven driver, a polled driver, both using and not using FIFO buffers. Nothing works. I have also tried various Tx/Rx clock rates and all four POL/PHA combinations. In all cases write work perfectly but reads always return zero.
MCSPI_CH0CONF Register = 0x2006_0CFC (also tried setting Bits[13:12] separately with write followed by read). Bit[20] is FORCE bit and this is set at start of operation and cleared at end of operation. All combinations of POL and PHA tried.
Register configuration after first (of 5) words sent and RX Full. RX always read zero?