A problem in SSI module

muhammad moutiry

Other Parts Discussed in Thread: TM4C123GH6PM

Hello ,

I have a problem in tm4c123gh6pm MCU , I am building my own device drivers for the tiva c

but in

SSI when I configure it , each register takes the correct values Except the SPDR ( SSI data register ) doesn't accept any value .

I checked the address of the data register and I am using code composer studio v6

over 8 years ago

0 Amit Ashara over 8 years ago

TI__Guru**** 244400 points

Hello Muhammad

The SPI data register is a FIFO entry register. When you write to the Data register the data goes to the TX FIFO. When you read from the data register, the data comes from the RX FIFO. So you cannot read what you have written. What you would be reading the SPI RX pin values shifted in and converted to parallel format as per the DSS configuration value.

0 muhammad moutiry over 8 years ago in reply to Amit Ashara

Intellectual 280 points

Is there any way that I can see the value that I have written to the data register , in order to make sure that everything goes well .

0 Amit Ashara over 8 years ago in reply to muhammad moutiry

TI__Guru**** 244400 points

Hello Muhammad

No, not by the CPU. The only way to do so is to see the SSITx Pin to confirm the data write and the bits being transmitted.

By using the CPU, the only known way is loopback mode, but then external device Tx pin (MISO) would not be connected to the Rx pin of the SSI controller

0 muhammad moutiry over 8 years ago in reply to Amit Ashara

Intellectual 280 points

Thank you very much , I tried the loopback mode and it works well .
Thanks , and sorry for disturbance.

0 Amit Ashara over 8 years ago in reply to muhammad moutiry

TI__Guru**** 244400 points

Hello Muhammad

The loopback mode is diagnostic only. It will not achieve anything functional when connected to a device which expects Data transmit and receive.

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A problem in SSI module