Other Parts Discussed in Thread: CC3220SF
Tool/software: TI-RTOS
Dear Support:
I am experiencing some weirdness with the CC3220 SPI driver that was hoping you could explain. I am using the CC3220SF LP and SDK v1.50 and using the following code to start a master SPI transaction:
SPI_Params_init(&MasterSpiParams);
MasterSpiParams.bitRate = 1000000;
MasterSpiParams.mode = SPI_MASTER;
MasterSpiParams.frameFormat = SPI_POL0_PHA1;
MasterSpiParams.transferCallbackFxn = HostSPI_CallbackFxn;
MasterSpiParams.transferMode = SPI_MODE_CALLBACK;
MasterSpiParams.transferTimeout = 100000;
MasterSpiParams.dataSize = 8;
hMasterSPI = SPI_open(CC3220SF_LAUNCHXL_SPI1, &MasterSpiParams);
if( hMasterSPI == NULL )
{
System_printf("SPI initialization failed! Leaving task...\n");
System_abort("Error initializing SPI\n");
return;
}
else
{
System_printf("SPI successfully initialized\n");
}
masterTransaction.rxBuf = NULL;
masterTransaction.txBuf = (uint8_t *)SPITaskInfo.TxtBuffer;
masterTransaction.count = 128;
transferOK = SPI_transfer(hMasterSPI, &masterTransaction);
if( transferOK )
{
Semaphore_pend( hSemaSPIVoice, BIOS_WAIT_FOREVER );
}
else
{
Message("Unsuccessful master SPI transfer");
}
This code is using a callback with the following callback function:
void HostSPI_CallbackFxn(SPI_Handle handle, SPI_Transaction *transaction)
{
Semaphore_post(hSemaSPIVoice);
}
where it posts a semaphore when the SPI transaction is completed. It is working, however it only transfer 2 bytes instead of the desired 128. In fact, no matter what I set the transfercount to, it only sends 2 bytes. However if I change this code to use a callback as such:
SPI_Params_init(&MasterSpiParams);
MasterSpiParams.bitRate = 1000000;
MasterSpiParams.mode = SPI_MASTER;
MasterSpiParams.frameFormat = SPI_POL0_PHA1;
MasterSpiParams.transferMode = SPI_MODE_BLOCKING;
MasterSpiParams.transferTimeout = 100000;
MasterSpiParams.dataSize = 8;
hMasterSPI = SPI_open(CC3220SF_LAUNCHXL_SPI1, &MasterSpiParams);
if( hMasterSPI == NULL )
{
System_printf("SPI initialization failed! Leaving task...\n");
System_abort("Error initializing SPI\n");
return;
}
else
{
System_printf("SPI successfully initialized\n");
}
masterTransaction.rxBuf = NULL;
masterTransaction.txBuf = (uint8_t *)SPITaskInfo.TxtBuffer;
masterTransaction.count = 128;
transferOK = SPI_transfer(hMasterSPI, &masterTransaction);
if( !transferOK )
{
Message("Unsuccessful master SPI transfer");
}
this works too, but except it only transfer 2 bytes instead of the desired 128. Reducing transfercount to 64 or less causes the desired number of bytes to transfer properly. To get it to transfer 128 bytes, I had to change the spiCC3220SDMAHWAttrs array in the CC3220SF_LAUNCHXL.c file as such:
const SPICC32XXDMA_HWAttrsV1 spiCC3220SDMAHWAttrs[CC3220SF_LAUNCHXL_SPICOUNT] = {
/* index 0 is reserved for LSPI that links to the NWP */
{
.baseAddr = LSPI_BASE,
.intNum = INT_LSPI,
.intPriority = (~0),
.spiPRCM = PRCM_LSPI,
.csControl = SPI_SW_CTRL_CS,
.csPolarity = SPI_CS_ACTIVEHIGH,
.pinMode = SPI_4PIN_MODE,
.turboMode = SPI_TURBO_OFF,
.scratchBufPtr = &spiCC3220SDMAscratchBuf[CC3220SF_LAUNCHXL_SPI0],
.defaultTxBufValue = 0,
.rxChannelIndex = UDMA_CH12_LSPI_RX,
.txChannelIndex = UDMA_CH13_LSPI_TX,
.minDmaTransferSize = 100,
.mosiPin = SPICC32XXDMA_PIN_NO_CONFIG,
.misoPin = SPICC32XXDMA_PIN_NO_CONFIG,
.clkPin = SPICC32XXDMA_PIN_NO_CONFIG,
.csPin = SPICC32XXDMA_PIN_NO_CONFIG
},
{
.baseAddr = GSPI_BASE,
.intNum = INT_GSPI,
.intPriority = (~0),
.spiPRCM = PRCM_GSPI,
.csControl = SPI_HW_CTRL_CS,
.csPolarity = SPI_CS_ACTIVELOW,
.pinMode = SPI_4PIN_MODE,
.turboMode = SPI_TURBO_OFF,
.scratchBufPtr = &spiCC3220SDMAscratchBuf[CC3220SF_LAUNCHXL_SPI1],
.defaultTxBufValue = 0,
.rxChannelIndex = UDMA_CH6_GSPI_RX,
.txChannelIndex = UDMA_CH7_GSPI_TX,
.minDmaTransferSize = 100,
.mosiPin = SPICC32XXDMA_PIN_07_MOSI,
.misoPin = SPICC32XXDMA_PIN_06_MISO,
.clkPin = SPICC32XXDMA_PIN_05_CLK,
.csPin = SPICC32XXDMA_PIN_08_CS
}
};
more specifically, I had to change the .minDmaTransferSize of the 2nd SPI entry from 100 to something greater that 128 like 130 and then the SPI transfer would perform a 128 byte transfer.
So by setting the .minDmaTransferSize to 130, all SPI transfers up to 128 worked successfully, but only when using blocking mode. However with .minDmaTransferSize at 100, a 128 byte transfercount only transfers 2 bytes. And when using the callback mode, all SPI transfers only transfer 2 bytes no matter what I set to transfercount to between 2 and 128.
Do you know what is going on here and preventing me from using the callback method and why i have to set .minDmaTransferSize to something greater that the transfercount to get it to work? Your thoughts?
Thanks,
Tim
