Hello Forum,
I am experiencing a strange behaviour on my XMC4200-based hardware:
I use USIC0,Ch1 for SPI to communicate with a peripheral chip.
Since the chip uses variable frame sizes, I chose WLE mode.
So far that worked out well, i can see the frames on the scope as expected and the responses seemed to be OK on the logic analyzer.
Here it gets interesting:
I now want to actually use the responses sent by the external IC in my software, but when I try
or even
the SPI TX FIFO seems to become corrupted. I get different frame sizes, different data, extra frames, the lot.
When I remove all reads of OUTR between the transmissions, everything is fine.
The reference manual mentions performance considerations when using concurrent access to the FIFO but no real restrictions.
What is going wrong here?
Regards,
Luke
my Send function:
my FIFO config:
I am experiencing a strange behaviour on my XMC4200-based hardware:
I use USIC0,Ch1 for SPI to communicate with a peripheral chip.
Since the chip uses variable frame sizes, I chose WLE mode.
So far that worked out well, i can see the frames on the scope as expected and the responses seemed to be OK on the logic analyzer.
Here it gets interesting:
I now want to actually use the responses sent by the external IC in my software, but when I try
Code:
XMC_SPI_CH_GetReceivedData(XMC_SPI0_CH1)Code:
(cvar) = XMC_SPI0_CH1->OUTRWhen I remove all reads of OUTR between the transmissions, everything is fine.
The reference manual mentions performance considerations when using concurrent access to the FIFO but no real restrictions.
What is going wrong here?
Regards,
Luke
my Send function:
Code:
void spiSendLTFrame(uint8_t cmd, uint16_t addr, uint8_t* data, uint8_t dlen)
{
uint8_t i;
XMC_SPI_CH_DisableDataTransmission(XMC_SPI0_CH1);
XMC_USIC_CH_TXFIFO_PutDataFLEMode(XMC_SPI0_CH1,cmd,SPI_WLE8);
XMC_USIC_CH_TXFIFO_PutDataFLEMode(XMC_SPI0_CH1,addr,SPI_WLE16);
for (i = 0; i< dlen; i++)
{
if (i == dlen-1)
XMC_USIC_CH_TXFIFO_PutDataFLEMode(XMC_SPI0_CH1,*data,SPI_WLE8|SPI_EOF);
else
XMC_USIC_CH_TXFIFO_PutDataFLEMode(XMC_SPI0_CH1,*data,SPI_WLE8);
data++;
}
XMC_SPI_CH_EnableDataTransmission(XMC_SPI0_CH1);
}Code:
/* Configure receive FIFO settings */
XMC_USIC_CH_RXFIFO_Configure(XMC_SPI0_CH1,
0U,
(XMC_USIC_CH_FIFO_SIZE_t)XMC_USIC_CH_FIFO_SIZE_8WORDS,
1U);
/* Configure transmit FIFO settings */
XMC_USIC_CH_TXFIFO_Configure(XMC_SPI0_CH1,
8U,
(XMC_USIC_CH_FIFO_SIZE_t)XMC_USIC_CH_FIFO_SIZE_16WORDS,
1U);