RTOS/MSP430F5529: SPI slave mode: the SPI_transfer() funtion issue

xc.mo

Intellectual 410 points

Part Number: MSP430F5529

Tool/software: TI-RTOS

my version:

ccsv7.4

tidriver_msp43x_2_20_00_08

bios_6_46_00_23

I'm still using the EXP_MSP430F5529LP development board to verify SPI communication, Recently , I'm stuck in the SPI_transfer() function. config spi slave mode under TI-RTOS.

target: SPI master sends a byte, spi slave judge the byte and to continue receiving or sending data.

here is my config

    /* Create I2C for usage */
    SPI_Params_init(&spiB1_slave_Params);
    spiB1_slave_Params.transferMode          = SPI_MODE_BLOCKING;
    spiB1_slave_Params.mode                       = SPI_SLAVE;
    spiB1_slave_Params.dataSize                 = 8;

    spiB1_slave = SPI_open(Board_SPIB1_SLAVE, &spiB1_slave_Params);
    if (spiB1_slave == NULL) {
        System_abort("Error Initializing SPI B1\n");
    }else {
        System_printf("SPI B1 Initialized!\n");
    }
    System_flush();

issue I use the following two pieces of code for data reception validation

	//code 1
	//disposable recept 3 bytes
        SPI_Transaction spiTransaction;        
		
	spiTransaction.txBuf = NULL;
	spiTransaction.rxBuf = rxBuf;
	spiTransaction.count = 3;

	if (SPI_transfer(spiB1_slave, &spiTransaction) == NULL) {
		System_printf("SPIB1_SendData SPI Bus fault\n");
		System_flush();
	}
	System_printf("%s\r\n",rxBuf);
	System_flush();
	
	
	
	//code 2
	//first recept 1 bytes
        SPI_Transaction spiTransaction;        
		
	spiTransaction.txBuf = NULL;
	spiTransaction.rxBuf = rxBuf;
	spiTransaction.count = 1;

	if (SPI_transfer(spiB1_slave, &spiTransaction) == NULL) {
		System_printf("SPIB1_SendData SPI Bus fault\n");
		System_flush();
	}
	
	//continue recept 2 bytes
	spiTransaction.txBuf = NULL;
	spiTransaction.rxBuf = rxBuf+1;
	spiTransaction.count = 2;

	if (SPI_transfer(spiB1_slave, &spiTransaction) == NULL) {
		System_printf("SPIB1_SendData SPI Bus fault\n");
		System_flush();
	}
	System_printf("%s\r\n",rxBuf);
	System_flush();

result

When I using the spi master send three bytes at a time, code 1 receive data is ok, buf code 1 will block in the second SPI_transfer();

When I using the spi master send three bytes each byte is one second apart, code 1 2 receive data both is ok.

Why is this problem?

best wishes

xc.mo

over 7 years ago

0 xc.mo over 7 years ago

Intellectual 410 points

There's a problem with my description.

When I using the spi master send three bytes at a time, code 1 receive data is ok, buf code 2 will block in the second SPI_transfer();

When I using the spi master send three bytes each byte is one second apart, code 1 2 receive data both is ok.

0 xc.mo over 7 years ago

Intellectual 410 points

issue 2. When I using the spi master send two bytes at a time, and slave module use code 3 , why receive data is ok?

When I using the spi master send three bytes at a time, and slave module use code 4 , why block in the second SPI_transfer()?

    //code 3 
    //recept two byte
    spiTransaction.txBuf = NULL;
    spiTransaction.rxBuf = rxBuf;
    spiTransaction.count = 1;

    if (SPI_transfer(spi_handle, &spiTransaction) == NULL) {
        System_printf("SPIB1_ReceData SPI Bus fault\n");
        System_flush();
    }

    spiTransaction.txBuf = NULL;
    spiTransaction.rxBuf = rxBuf+1;
    spiTransaction.count = 1;

    if (SPI_transfer(spi_handle, &spiTransaction) == NULL) {
        System_printf("SPIB1_SendData SPI Bus fault\n");
        System_flush();
    }


    //code 4 
    //recept three byte
    spiTransaction.txBuf = NULL;
    spiTransaction.rxBuf = rxBuf;
    spiTransaction.count = 1;

    if (SPI_transfer(spi_handle, &spiTransaction) == NULL) {
        System_printf("SPIB1_ReceData SPI Bus fault\n");
        System_flush();
    }

    spiTransaction.txBuf = NULL;
    spiTransaction.rxBuf = rxBuf+1;
    spiTransaction.count = 1;

    if (SPI_transfer(spi_handle, &spiTransaction) == NULL) {
        System_printf("SPIB1_SendData SPI Bus fault\n");
        System_flush();
    }

    spiTransaction.txBuf = NULL;
    spiTransaction.rxBuf = rxBuf+2;
    spiTransaction.count = 1;
    //note: will block here
    if (SPI_transfer(spi_handle, &spiTransaction) == NULL) {
        System_printf("SPIB1_SendData SPI Bus fault\n");
        System_flush();
    }

thank you

0 xc.mo over 7 years ago in reply to xc.mo

Intellectual 410 points

issue 3: When I using the spi master send three bytes at a time, and slave module use code 5 , why receive data is ok?

    //code 5
    //first recept 2 byte
    spiTransaction.txBuf = NULL;
    spiTransaction.rxBuf = rxBuf;
    spiTransaction.count = 2; //

    if (SPI_transfer(spi_handle, &spiTransaction) == NULL) {
        System_printf("SPIB1_ReceData SPI Bus fault\n");
        System_flush();
    }

    spiTransaction.txBuf = NULL;
    spiTransaction.rxBuf = rxBuf+2;
    spiTransaction.count = 1;

    if (SPI_transfer(spi_handle, &spiTransaction) == NULL) {
        System_printf("SPIB1_SendData SPI Bus fault\n");
        System_flush();
    }

0 Cameron LaFollette over 7 years ago in reply to xc.mo

TI__Genius 14875 points

xc.mo,
I've looped in our RTOS experts, but they are on vacation, so responses will be delayed till at least the 29th.

0 xc.mo over 7 years ago in reply to Cameron LaFollette

Intellectual 410 points

Hi Cameron

Thank you very much for your help, although I added a delay to spi master module to avoid the problem of spi slave block the SPI_transfer() function, I would like to know why.