EK-TM4C1294XL: SPI Slave Mode

I use example ssi_master_slave_xfer. I try 10 times to get the same sequence, but each time I get a new array of 8 elements...

void
SSI2IntHandler(void)
{
    uint32_t ui32Status;

    //
    // Read SSIMIS (SSI Masked Interrupt Status).
    //
    ui32Status = MAP_SSIIntStatus(SSI2_BASE, true);

    //
    // Clear the SSI interrupt.
    //
    MAP_SSIIntClear(SSI2_BASE, ui32Status);

    //
    // Turn off the RX FIFO interrupt.
    //
    MAP_SSIIntDisable(SSI2_BASE, SSI_RXFF);

    g_breceiveFlag = 1;
}

int t=0;

    while (t<10)
    {
        //
        // Wait until SSI1 receives the half-full interrupt on the RX FIFO.
        //
        while (g_breceiveFlag == 0);

        //
        // Display indication that the SSI0 is receiving data.
        //
        //
        // Receive 4 bytes of data.
        //
        for(ui32Index = 0; ui32Index < NUM_SSI_DATA; ui32Index++)
        {
            //
            // Receive the data using the "blocking" Get function.  This function
            // will wait until there is data in the receive FIFO before returning.
            //
            MAP_SSIDataGet(SSI2_BASE, &pui32DataRx[ui32Index]);

            //
            // Since we are using 16-bit data, mask off the MSB.
            //
            //pui32DataRx[ui32Index] &= 0xFFFF;

            //
            // Display the data that SSI0 received.
            //
            //UARTprintf("'%d' ", pui32DataRx[ui32Index]);
        }


        UARTprintf("\nSSI2 Received: '%d' \n", t);
        for(ui32Index = 0; ui32Index < NUM_SSI_DATA; ui32Index++)
        {
            pui32DataRx[ui32Index] &= 0xFFFF;
            //
            // Display the data that SSI0 received.
            //
            UARTprintf("'%d' ", pui32DataRx[ui32Index]);
        }
        UARTprintf("\n\nMaster-Slave Transfer Complete.\n");


        //
        // Display indication that the SSI1 is receiving data.
        //
        t++;
    }

SSI2 Received: '1'
'43250' '43251' '43252' '43253' '43254' '43255' '43256' '43249'

Master-Slave Transfer Complete.

SSI2 Received: '2'
'43253' '43254' '43255' '43256' '43249' '43250' '43251' '43252'

Master-Slave Transfer Complete.

SSI2 Received: '3'
'43249' '43250' '43251' '43252' '43253' '43254' '43255' '43256'

Master-Slave Transfer Complete.

SSI2 Received: '4'
'43252' '43253' '43254' '43255' '43256' '43249' '43250' '43251'

Master-Slave Transfer Complete.

SSI2 Received: '5'
'43256' '43249' '43250' '43251' '43252' '43253' '43254' '43255'

Master-Slave Transfer Complete.

SSI2 Received: '6'
'43252' '43253' '43254' '43255' '43256' '43249' '43250' '43251'

Master-Slave Transfer Complete.

SSI2 Received: '7'
'43255' '43256' '43249' '43250' '43251' '43252' '43253' '43254'

Master-Slave Transfer Complete.

SSI2 Received: '8'
'43251' '43252' '43253' '43254' '43255' '43256' '43249' '43250'

Master-Slave Transfer Complete.

SSI2 Received: '9'
'43254' '43255' '43256' '43249' '43250' '43251' '43252' '43253'

Master-Slave Transfer Complete.

Array from master: '43249' '43250' '43251' '43252' '43253' '43254' '43255' '43256'

Waveform:

Hi,

  I think after the below line you need to reset the g_breceiveFlag to 0 again. 

        while (g_breceiveFlag == 0);

        g_breceiveFlag = 0; // Add this line

It seems to work with TivaWare, how now to repeat the same thing in RTOS. How to handle SSI_RXFF interrupt in RTOS and transfer it to hwi.

Hi,

  Please go to section 5 Using Hwi on this TI-RTOS Workshop training for details about setting up Hwi. Page 166 has examples to setup Hwi for Tiva MCU. 

https://training.ti.com/sites/default/files/docs/TI_RTOS_Kernel_Workshop_Student_Guide_rev4.00.pdf

Below is an example to setup the Hwi for Timer2A. 

//----------------------------------------
// BIOS header files
//----------------------------------------
#include <xdc/std.h>  						//mandatory - have to include first, for BIOS types
#include <ti/sysbios/BIOS.h> 				//mandatory - if you call APIs like BIOS_start()
#include <xdc/runtime/Log.h>				//needed for any Log_info() call
#include <xdc/cfg/global.h> 				//header file for statically defined objects/handles
#include <xdc/runtime/System.h>
#include <xdc/runtime/Error.h>
#include <ti/sysbios/hal/Hwi.h>


//------------------------------------------
// TivaWare Header Files
//------------------------------------------
#include <stdint.h>
#include <stdbool.h>

#include "inc/hw_types.h"
#include "inc/hw_memmap.h"
#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"
#include "inc/hw_ints.h"
#include "driverlib/interrupt.h"
#include "driverlib/timer.h"


//----------------------------------------
// Prototypes
//----------------------------------------
void hardware_init(void);
void ledToggle(void);


//---------------------------------------
// Globals
//---------------------------------------
volatile int16_t i16ToggleCount = 0;


//---------------------------------------------------------------------------
// main()
//---------------------------------------------------------------------------
void main(void)
{

    hardware_init();                         // init hardware via Xware

    Hwi_Params hwiParams;
    Hwi_Handle myHwi;
    Error_Block eb;
    /* Initialize error block and hwiParams to default values */
    Error_init(&eb);
    Hwi_Params_init(&hwiParams);
    hwiParams.enableInt = FALSE;
    myHwi = Hwi_create(39, (Hwi_FuncPtr)ledToggle, &hwiParams, &eb);
    if (myHwi == NULL) {
    System_abort("Hwi create failed");
    }
    Hwi_enableInterrupt(39);


   BIOS_start();

}


//---------------------------------------------------------------------------
// hardware_init()
//
// inits GPIO pins for toggling the LED
//---------------------------------------------------------------------------
void hardware_init(void)
{
	uint32_t ui32Period;

	//Set CPU Clock to 40MHz. 400MHz PLL/2 = 200 DIV 5 = 40MHz
	SysCtlClockSet(SYSCTL_SYSDIV_5|SYSCTL_USE_PLL|SYSCTL_XTAL_16MHZ|SYSCTL_OSC_MAIN);

	// ADD Tiva-C GPIO setup - enables port, sets pins 1-3 (RGB) pins for output
	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
	GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3);

	// Turn on the LED
	GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3, 4);

	// Timer 2 setup code
	SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER2);			// enable Timer 2 periph clks
	TimerConfigure(TIMER2_BASE, TIMER_CFG_PERIODIC);		// cfg Timer 2 mode - periodic

	ui32Period = (SysCtlClockGet() /2);						// period = CPU clk div 2 (500ms)
	TimerLoadSet(TIMER2_BASE, TIMER_A, ui32Period);			// set Timer 2 period

	TimerIntEnable(TIMER2_BASE, TIMER_TIMA_TIMEOUT);		// enables Timer 2 to interrupt CPU

	TimerEnable(TIMER2_BASE, TIMER_A);						// enable Timer 2

}


//---------------------------------------------------------------------------
// ledToggle()
//
// toggles LED on Tiva-C LaunchPad
//---------------------------------------------------------------------------
void ledToggle(void)
{
    TimerIntClear(TIMER2_BASE, TIMER_TIMA_TIMEOUT);			// must clear timer flag FROM timer

	// LED values - 2=RED, 4=BLUE, 8=GREEN
	if(GPIOPinRead(GPIO_PORTF_BASE, GPIO_PIN_2))
	{
		GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3, 0);
	}
	else
	{
		GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, 4);
	}

	i16ToggleCount += 1;									// keep track of #toggles

	Log_info1("LED TOGGLED [%u] TIMES",i16ToggleCount);		// send toggle count to UIA

}