TMS320F28P650DK: Is it possible to send 40 bits via spi?

Hi,

Kindly refer to this thread: LAUNCHXL-F28379D: Sending 24 bit word from txt file via spi - C2000 microcontrollers forum - C2000︎ microcontrollers - TI E2E support forums

Best Regards,

Aishwarya

Hi :)

If I set the data width to 16 in the sysconf I can insert this command as desired and can therefore send the multiple of 16 bits (here 64Bits) in a chip select:










The problem is that 40 is not a multiple of 16. That's why I just set the data width to 8 in the sysconf. However, I can no longer execute SPI_writeDataNonBlocking(SPIB_BASE, 0xAA). No data is visible on the oscilloscope (chip select and clk are visible but not data). What else do I have to change so that I can execute the command more often in order to be able to send a multiple of 8 bits?

My code:

#include "driverlib.h"
#include "device.h"
#include "board.h"

//
// Globals
//
volatile uint16_t receiveData;
volatile uint16_t slaveReady = 0;
volatile uint16_t masterReady = 0;
volatile uint16_t counter = 1;

//
// Function Prototypes
//
__interrupt void spibTxFIFOISR(void);
__interrupt void spiaRxFIFOISR(void);

//
// Main
//
void main(void)
{
    uint16_t i;

    //
    // Initialize device clock and peripherals
    //
    Device_init();

    //
    // Disable pin locks and enable internal pullups.
    //
    Device_initGPIO();

    //
    // Initialize PIE and clear PIE registers. Disables CPU interrupts.
    //
    Interrupt_initModule();

    //
    // Initialize the PIE vector table with pointers to the shell Interrupt
    // Service Routines (ISR).
    //
    Interrupt_initVectorTable();

    //
    // Board initialization
    //
    Board_init();
    //
    // Enable Global Interrupt (INTM) and realtime interrupt (DBGM)
    //
    EINT;
    ERTM;

    //
    // Loop forever. Suspend or place breakpoints to observe the buffers.
    //
    while (1)
    {
        ;
    }
}

//
// SPI B Transmit FIFO ISR
//
__interrupt void spibTxFIFOISR(void)
{
    uint16_t i = 0;

    //
    // Send data
    //

    while (i < 10000)
    {
        i++;
    }

    SPI_writeDataNonBlocking(SPIB_BASE, 0xAA);
    SPI_writeDataNonBlocking(SPIB_BASE, 0xAA);

    SPI_writeDataNonBlocking(SPIB_BASE, 0xAA);
    SPI_writeDataNonBlocking(SPIB_BASE, 0xAA);

    //
    // Clear interrupt flag and issue ACK
    //
    SPI_clearInterruptStatus(SPIB_BASE, SPI_INT_TXFF);
    Interrupt_clearACKGroup(INT_SPIB_controller_TX_INTERRUPT_ACK_GROUP);

}

//
// Enabled only for SysConfig functionality
//
__interrupt void INT_SPIB_controller_RX_ISR(void)
{
    //
    // Issue ACK
    //
    Interrupt_clearACKGroup(INT_SPIB_controller_RX_INTERRUPT_ACK_GROUP);

}

//
// End of file
//