RTOS/EK-TM4C129EXL: SPI Master Transfer Fail

Dillon Wiggins

Part Number: EK-TM4C129EXL

Tool/software: TI-RTOS

I can not get SPI working on the TM4C.

SPI Initialize code:

    SPI_Params spiParams;
    SPI_init();  // Initialize the SPI driver
    SPI_Params_init(&spiParams);  // Initialize SPI parameters
    spiParams.transferMode = SPI_MODE_BLOCKING;
    spiH = SPI_open(Board_SPI0, &spiParams);
    if(!spiH)
        while(1);

Calling the transfer function within task:

        spiTransaction.count = 8;
        spiTransaction.txBuf = (Ptr)spiTxBuff;
        spiTransaction.rxBuf = (Ptr)spiRxBuff;

        spitransferOK = SPI_transfer(spiH, &spiTransaction);

From ROV I see this exception under Hwi:

Hard Fault: FORCED: MEMFAULT: IACCVIOL Instruction Fetch Error. Address = 0xe000ed34

I have already tried increasing my task stack size and increasing the Hwi stack size.

I am using the basic blank project for TI-RTOS TM4C updated to serve as an http server.

Thank you,

Dillon

over 6 years ago

0 ToddMullanix over 6 years ago

TI__Guru* 96960 points

Hi Dillon,

What does the back trace show in the ROV->Hwi->Exceptions view? Also, there's this video/ppt that talks about exceptions that might be helpful: training.ti.com/debugging-common-application-issues-ti-rtos

Todd

0 Dillon Wiggins over 6 years ago in reply to ToddMullanix

Intellectual 400 points

Here is all the information from ROV for the exception. I looked over the SPI loop-back example and can not find a reason that SPI should not work in my application. Thank you for your help.

0 ToddMullanix over 6 years ago in reply to Dillon Wiggins

TI__Guru* 96960 points

Hi Dillon,

There's a couple nuggets in the picture.

1. The exception occurred during Task context in the 0x20013a78 task. You can look in ROV->Tasks->Detailed to see which task this is.
2. The PC is 0xbebebebe which is what TI-RTOS initializes all the stacks (task and system) to be default. You probably jumped there due to an uninitialized local variable or bad pointer.

If the callstack in ROV->Tasks->Call Stacks does not give you anymore information, you'll probably need to put something in the task to figure out where the problem is occurring (e.g. global counters that are incremented or LED flashing).

Todd