CCS/ADS1220: How can I get the conversion data?

Hi Bob.

Thank you for your help.

I tried the method of reading the data direct.

First, check the /DRDY by external interrupt 1.

Send, set CS low and by transmitting 3 dummy bytes (NOP) of data to initiate the SCLKs.  read the buffer when the RX interrupt occurred, After the 3 bytes of data are received , set CS high.

Here is the codes and captured image.

Interrupt Setup ---------------------------------

//
// Enable XINT1 and XINT2 in the PIE: Group 1 interrupt 4 & 5
// Enable INT1 which is connected to WAKEINT
//
PIE_enable(obj->pieHandle); // Enable the PIE block
PIE_enableInt(obj->pieHandle, PIE_GroupNumber_1, PIE_InterruptSource_XINT_1); // Enable PIE Group 1 INT4
CPU_enableInt(obj->cpuHandle, CPU_IntNumber_1); // Enable CPU INT1

// SPI TX,RX
PIE_enableInt(obj->pieHandle, PIE_GroupNumber_6, PIE_InterruptSource_SPIARX); // Enable PIE Group 6, INT 1
CPU_enableInt(obj->cpuHandle, CPU_IntNumber_6); // Enable CPU INT6
EINT; // Enable Global Interrupts

//
// GPIO29 is XINT1
//
EALLOW;
GPIO_setExtInt(obj->gpioHandle,GPIO_Number_29,CPU_ExtIntNumber_1); // XINT1 is GPIO29
EDIS;

//
// Configure XINT1 and XINT2
//
PIE_setExtIntPolarity(obj->pieHandle, CPU_ExtIntNumber_1, PIE_ExtIntPolarity_FallingEdge);

//
// Enable XINT1 and XINT2
//
PIE_enableExtInt(obj->pieHandle, CPU_ExtIntNumber_1);

//
// GPIO19 will go low inside each interrupt.
//
EALLOW;
// SPI-STE
GPIO_setMode(obj->gpioHandle,GPIO_Number_19,GPIO_19_Mode_GeneralPurpose); //GPIO_19_Mode_SPISTEA_NOT
GPIO_setDirection(obj->gpioHandle,GPIO_Number_19,GPIO_Direction_Output);
GPIO_setPullup(obj->gpioHandle,GPIO_Number_19,GPIO_Pullup_Enable);
EDIS;

EINT; // Enable Global Interrupts

SPI-A Setup ------------------------------------------------------------

//! Reset SPI for changing configuration
SPI_reset(obj->spiAHandle);

//! SPI CCR (Configuration Control Register)
SPI_setClkPolarity(obj->spiAHandle,SPI_ClkPolarity_OutputRisingEdge_InputFallingEdge);
SPI_disableLoopBack(obj->spiAHandle);
SPI_setCharLength(obj->spiAHandle,SPI_CharLength_8_Bits);

//! SPI CTL (Operation Control Register)
SPI_enableOverRunInt(obj->spiAHandle); // the OVERRUN INT ENA bits in the SPICTL register
SPI_setClkPhase(obj->spiAHandle,SPI_ClkPhase_Normal); // the CLOCK PHASE bits in the SPICTL register
SPI_setMode(obj->spiAHandle,SPI_Mode_Master); // he MASTER/SLAVE bits in the SPICTL register
SPI_enableTx(obj->spiAHandle); // the TALK bits in the SPICTL register

//! SPI ST (Status Register)
obj->spiAHandle->SPIST = 0x0000;

//! SPI BBR (Baud Rate Register)
//! BaudRate setting is not needed for slave mode
//! 4MHz for Turbo Mode 2KSPS, so SPIBRR = 21, 4MHz
SPI_setBaudRate(obj->spiAHandle,(SPI_BaudRate_e)(0x0015)); // 0001 0101 --> 101, 5MHz

//! SPI FFTX (Transmit Register): 1100 0000 0010 0010
SPI_enableChannels(obj->spiAHandle); // Reset the SPI RX/TX channels
SPI_enableTxFifoEnh(obj->spiAHandle); // FIFO enhancements enable
SPI_clearTxFifoInt(obj->spiAHandle); // TX FIFO Interrupt Clear
SPI_enableTxFifoInt(obj->spiAHandle); // TX FIFO Interrupt enable
SPI_setTxFifoIntLevel(obj->spiAHandle, SPI_FifoLevel_1_Word); //set TX FIFO level to 2

//! SPI FFRX (Receive Register) : 0x0022 (10 0010)
SPI_enableRxFifoInt(obj->spiAHandle); // RX FIFO Interrupt enable
SPI_setRxFifoIntLevel(obj->spiAHandle, SPI_FifoLevel_2_Words); //set RX FIFO level to 2

//! SPI FFCT (FIFO Control Register)
SPI_setTxDelay(obj->spiAHandle,0);

//! SPI PRI (Priority Control Register)
SPI_setSuspend(obj->spiAHandle,SPI_TxSuspend_free);

//! Enable SPI
SPI_enable(obj->spiAHandle); // Enable SPI

//! TX FIFO Reset, RX FIFO Reset
SPI_enableTxFifo(obj->spiAHandle); // Transmit FIFO reset
SPI_enableRxFifo(obj->spiAHandle); // Receive FIFO reset

ISR Routine -----------------------------------

interrupt void spiRdyISR(void)
{

    HAL_Obj  *obj = (HAL_Obj *)halHandle;

GPIO_setLow(obj->gpioHandle, GPIO_Number_19); // SPI-STE

// Wait for the ADS1220 registers to update
delayLoop(1); //usec

// initiate the SCLKs.
spiTxDummyData();

HAL_acqAdsRdyInt(halHandle); // Acknowledge interrupt from PIE group 1, CPU INT1

}

interrupt void spiRxFifoISR(void)
{
HAL_Obj *obj = (HAL_Obj *)halHandle;

while(SPI_getRxFifoStatus(obj->ads1220Handle->spiHandle) != SPI_FifoLevel_Empty)
{
gSpiVars.RxData[gSpiVars.RxNum++] = SPI_read(obj->ads1220Handle->spiHandle);
}

GPIO_setHigh(obj->ads1220Handle->gpioHandle, GPIO_Number_19);

// Clear Overflow flag
SPI_clearRxFifoOvf(obj->ads1220Handle->spiHandle);

// Clear Interrupt flag
SPI_clearRxFifoInt(obj->ads1220Handle->spiHandle);

// Acknowledge interrupt from PIE group 6, CPU INT6
HAL_acqAdsSpiInt(halHandle);

return;

}