[参考译文] TMS320F28379D：ADS1258：读取 CONFIG0 默认寄存器值

https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1550725/tms320f28379d-ads1258-read-config0-default-register-value

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我之前创建了一个线程、但对它的响应很少、因此我在这里创建了一个新线程。 我使用的是 TMS320F28379D 控制器、我通过 SPI 通信与 ADS1258 连接。 我的主要任务是读取 ADS1258 的默认 CONFIG0 寄存器、其默认值为 0x0A。

1) 在读取默认寄存器时、我是否需要将 PWDN 和 RESET 引脚设为高电平、或者是否可以直接运行默认寄存器读取代码？

2) ADS1258 在模式 00 (CPOL = 0、CPHA = 0) 下使用 SPI 进行通信、因此在 TMS320F28379D 设置中、我设置了 CLKPOLARITY = 0 和 CLK_PHASE = 0。

3) 我将数据 0x40、0x00 发送到 ADS1258。 我还附上了一个波形。 请进行验证。我发送了连续数据、只是为了使波形可见、因为我无法在单次模式下捕获。

4) 我已将通信频率设置为 1MHz、并附上了代码。

请仔细查看我的代码、并准确告诉我可能出错的地方。 我已经尝试读取默认寄存器将近一个月了、因此我确实需要帮助。

#include "F28x_Project.h"
#include "ADS1258.h"


static uint8_t registerMap[NUM_REGISTERS];
uint8_t DataTx[2] = { 0 };
uint8_t DataRx[2] = { 0 };

void main(void)
{
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the F2837xD_SysCtrl.c file   InitSysCtrl();

// Step 2. Initialize GPIO:
// This example function is found in the F2837xD_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// Setup only the GPIO only for SPI-A functionality
// This function is found in F2837xD_Spi.c
   InitSpiaGpio();
   InitADS1258Gpio();

// Step 3. Clear all interrupts:
   DINT;

//
// Initialize PIE control registers to their default state.
// The default state is all PIE __interrupts disabled and flags
// are cleared.
// This function is found in the F2837xD_PieCtrl.c file.\
   InitPieCtrl();

// Disable CPU __interrupts and clear all CPU __interrupt flags:
   IER = 0x0000;
   IFR = 0x0000;

// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the __interrupt
// is not used in this example.  This is useful for debug purposes.
// The shell ISR routines are found in F2837xD_DefaultIsr.c.
// This function is found in F2837xD_PieVect.c.
   InitPieVectTable();

// Step 4. Initialize the Device Peripherals:
   spi_fifo_init();     // Initialize the SPI FIFO

// Step 5. User specific code:
   adcStartupRoutine();

   for(;;)
   {

   }
}

void adcStartupRoutine(void)
{
    /* (OPTIONAL) Provide additional delay time for power supply settling */
    DELAY_US(50000);

    GpioDataRegs.GPBSET.bit.GPIO61 = 1; // CS HIGH

    /* (REQUIRED) Set nRESET/nPWDN pin high for ADC operation */
    GpioDataRegs.GPBCLEAR.bit.GPIO52 = 1;    // PWDN low
    DELAY_US(100);
    GpioDataRegs.GPBCLEAR.bit.GPIO52 = 1;    // PWDN high
    DELAY_US(10000);

    /* (REQUIRED) tWAKE delay */
    DELAY_US(5000);

    readSingleRegister(0X00);
}

uint8_t spiSendReceiveByte(uint8_t data)
{
    // Wait if TX buffer is full
    while (SpiaRegs.SPISTS.bit.BUFFULL_FLAG);

    // Send data (upper byte only transmitted)
    SpiaRegs.SPITXBUF = ((uint16_t)data << 8);
}


void spiSendReceiveArrays(uint8_t DataTx[], uint8_t DataRx[], uint8_t byteLength)
{

    volatile uint16_t dummy;

    /* Set the nCS pin LOW */
    GpioDataRegs.GPBCLEAR.bit.GPIO61 = 1;   // CS LOW

    uint8_t i;
    for (i = 0; i < byteLength; i++)
    {
        spiSendReceiveByte(DataTx[i]);
    }

    spiSendReceiveByte(0x00);
    if (SpiaRegs.SPISTS.bit.BUFFULL_FLAG == 1)
    {
       DataRx[0] =(SpiaRegs.SPIRXBUF >> 8);
    }

    spiSendReceiveByte(0x00);
    if (SpiaRegs.SPISTS.bit.BUFFULL_FLAG == 1)
    {
         DataRx[1] =(SpiaRegs.SPIRXBUF >> 8);
    }

    GpioDataRegs.GPBSET.bit.GPIO61 = 1; // CS HIGH
}

void spi_fifo_init()
{
    //
    // Initialize SPI FIFO registers
    //
    SpiaRegs.SPIFFTX.all = 0xE040;
    SpiaRegs.SPIFFRX.all = 0x2044;
    SpiaRegs.SPIFFCT.all = 0x0;

    //
    // Initialize core SPI registers
    //
    InitSpi();
}

void InitADS1258Gpio(void)
{
    EALLOW;

    GpioCtrlRegs.GPBMUX2.bit.GPIO52 = 0;  // GPIO80 as GPIO
    GpioCtrlRegs.GPBDIR.bit.GPIO52 = 1;   // Output (PWDN)

    GpioCtrlRegs.GPDMUX1.bit.GPIO97 = 0;  // GPIO84 as GPIO
    GpioCtrlRegs.GPDDIR.bit.GPIO97 = 1;   // Output (RESET)

    GpioCtrlRegs.GPCMUX1.bit.GPIO67 = 0;   // GPIO4 as GPIO
    GpioCtrlRegs.GPCDIR.bit.GPIO67 = 1;    // Output (START)

    GpioCtrlRegs.GPBMUX2.bit.GPIO61 = 0;   // GPIO4 as GPIO
    GpioCtrlRegs.GPBDIR.bit.GPIO61 = 1;    // Output (CS)

    EDIS;

}

uint8_t readSingleRegister(uint8_t address)
{
    /* Build TX array and send it */
    DataTx[0] = OPCODE_RREG | (address & OPCODE_A_MASK);
    spiSendReceiveArrays(DataTx, DataRx, 2);

    /* Update register array and return read result*/
    registerMap[address] = DataRx[1];
    return DataRx[1];
}
void InitSpi(void)
{
    // Initialize SPI-A

    // Set reset low before configuration changes
    // Clock polarity (0 == rising, 1 == falling)
    // 16-bit character
    // Enable loop-back
    SpiaRegs.SPICCR.bit.SPISWRESET = 0;

    SpiaRegs.SPIPRI.bit.TRIWIRE = 1;
    SpiaRegs.SPICCR.bit.CLKPOLARITY = 0;
    SpiaRegs.SPICCR.bit.SPICHAR = 7;
    SpiaRegs.SPICCR.bit.SPILBK = 0;

    // Enable master (0 == slave, 1 == master)
    // Enable transmission (Talk)
    // Clock phase (0 == normal, 1 == delayed)
    // SPI interrupts are disabled
    SpiaRegs.SPICTL.bit.MASTER_SLAVE = 1;
    SpiaRegs.SPICTL.bit.TALK = 1;
    SpiaRegs.SPICTL.bit.CLK_PHASE = 0;
    SpiaRegs.SPICTL.bit.SPIINTENA = 0;

    // Set the baud rate
    SpiaRegs.SPIBRR.bit.SPI_BIT_RATE = 24;

    // Set FREE bit
    // Halting on a breakpoint will not halt the SPI
    SpiaRegs.SPIPRI.bit.FREE = 1;

    // Release the SPI from reset
    SpiaRegs.SPICCR.bit.SPISWRESET = 1;
}

void InitSpiGpio()
{
   InitSpiaGpio();
}

//
// InitSpiaGpio - Initialize SPIA GPIOs
//
void InitSpiaGpio()
{
   EALLOW;

    //
    // Enable internal pull-up for the selected pins
    //
    // Pull-ups can be enabled or disabled by the user.
    // This will enable the pullups for the specified pins.
    // Comment out other unwanted lines.
    //
    GpioCtrlRegs.GPBPUD.bit.GPIO58 = 0;  // Enable pull-up on GPIO16 (SPISIMOA)
    GpioCtrlRegs.GPBPUD.bit.GPIO59 = 0;  // Enable pull-up on GPIO17 (SPISOMIA)
    GpioCtrlRegs.GPBPUD.bit.GPIO60 = 0;  // Enable pull-up on GPIO18 (SPICLKA)
    GpioCtrlRegs.GPBPUD.bit.GPIO61 = 0;  // Enable pull-up on GPIO19 (SPISTEA)

    //
    // Set qualification for selected pins to asynch only
    //
    // This will select asynch (no qualification) for the selected pins.
    // Comment out other unwanted lines.
    //
    GpioCtrlRegs.GPBQSEL2.bit.GPIO58 = 3; // Asynch input GPIO16 (SPISIMOA)
    GpioCtrlRegs.GPBQSEL2.bit.GPIO59 = 3; // Asynch input GPIO17 (SPISOMIA)
    GpioCtrlRegs.GPBQSEL2.bit.GPIO60 = 3; // Asynch input GPIO18 (SPICLKA)
    GpioCtrlRegs.GPBQSEL2.bit.GPIO61 = 3; // Asynch input GPIO19 (SPISTEA)


    GpioCtrlRegs.GPBGMUX2.bit.GPIO58 = 3; // Configure GPIO16 as SPISIMOA
    GpioCtrlRegs.GPBGMUX2.bit.GPIO59 = 3; // Configure GPIO17 as SPISOMIA
    GpioCtrlRegs.GPBGMUX2.bit.GPIO60 = 3; // Configure GPIO18 as SPICLKA
    GpioCtrlRegs.GPBGMUX2.bit.GPIO61 = 3; // Configure GPIO19 as SPISTEA
    //
    //Configure SPI-A pins using GPIO regs
    //
    // This specifies which of the possible GPIO pins will be SPI functional
    // pins.
    // Comment out other unwanted lines.
    //
    GpioCtrlRegs.GPBMUX2.bit.GPIO58 = 3; // Configure GPIO16 as SPISIMOA
    GpioCtrlRegs.GPBMUX2.bit.GPIO59 = 3; // Configure GPIO17 as SPISOMIA
    GpioCtrlRegs.GPBMUX2.bit.GPIO60 = 3; // Configure GPIO18 as SPICLKA
    GpioCtrlRegs.GPBMUX2.bit.GPIO61 = 3; // Configure GPIO19 as SPISTEA

    EDIS;
}