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Hello Patrick,

If you read the SSI section of the data sheet, it mentions that for every byte put, there would be a byte get. So if you need to only transmit data (.g. lets say 3 bytes), then you need to flush 3 bytes from the RXFIFO. If then you want to receive 3 bytes, then you need to write 3 dummy bytes.

So the first thing you need to do is to update the function so that in write functions, the FIFO is flushed.

Regards
Amit

Hello Patrick,

In the Transmit function I am expecting that every operation of SSIDataPut be followed by SSIDataGet

As an example

SSIDataPut(SSI2_BASE, 0x7F); //Send dummy data
while(SSIBusy(SSI2_BASE)){}

should be

SSIDataPut(SSI2_BASE, 0x7F); //Send dummy data
SSIDataGet(SSI2_BASE, $dummyByte); //Send dummy data


Also in flush operation, there should only be SSIDataGetNonBlocking and no SSIDataPut.

Please check the SSI example in TivaWare path D:\ti\TivaWare_C_Series-2.1.2.111\examples\peripherals\ssi\spi_master.c

Regards
Amit

Hello Patrick,

Can you please pasted the updated code...

Regards
Amit Ashara

Hello Patrick,

I do not see anything wrong in the code. The only suggestion would be that ssi init and disable need not be done in a loop. Init can be done once outside the main loop and then only send and receive functions called.

I would suggest connecting a LA or a scope to see what is happening on the bus?

Regards
Amit

Hello Patrick

I am not sure what you mean by this

Patrick Ruesch said:

But I have to flush the FIFOs manually every time with SFTX an SFRX command strobes. Is this normal?

Regards

Amit Ashara

Hello Patrick

I may suggest using the Advanced mode, as it would be useful as dummy reads can be eliminated. All the best.

Regards
Amit