According to the TI0RTOS 1.21 Getting started guide
The txBuf and rxBuf parameters are both pointers to data buffers. If txBuf is NULL, the driver sends SPI
frames with all data bits set to 0. If rxBuf is NULL, the driver discards all SPI frames received.
However when I set up an SPI transaction and set the rxBuf pointer to NULL I get a program termination.
As I am writing to an LCD which cannot supply data back it is very wasteful to need a Receive buffer.
I am using latest TIRTOS release tirtos_1_21_00_09
My code for the transfer works with an Rx buffer, crashes with Rxbuffer set to 0.
// Initialise LCD SPI transaction structure
lcdTransaction.
count = Size;
lcdTransaction.
txBuf = (Ptr)ui8Data;
lcdTransaction.
rxBuf = (Ptr)lcdRxBuffer;
// Initiate SPI transfer
lcdTransferOK =
SPI_transfer(LCD_SPI, &lcdTransaction);