[参考译文] MSPM0G3507：SPI 不返回寄存器值

https://e2e.ti.com/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1457473/mspm0g3507-spi-not-returning-register-values

工具与软件：

专家、您好！ 新年快乐！

我正在开发用于写入和读取外部 存储器的固件(MB85RS256B 是 FRAM、Fujitsu)。

为此、我很幸运地在这里找到了一个示例(代码的第4行有链接)。 我能够读取存储器 ID、就像最初实现的示例一样。

然后、我 将示例中的一个小标题更改为合并写入过程。 我想说它仍然可以工作(示波器看起来正常吗？)、但是 gRxPacket 变量(我的代码的第80行)始终为零。

请、有人能给我任何关于我做错了什么的提示吗？

#include "ti_msp_dl_config.h"

/* Code example: 
e2e.ti.com/.../5551850
peripheral: MB85RS256B is a FRAM, Fujitsu
*/

#define SPI_PACKET_SIZE_TX (5)
#define SPI_PACKET_SIZE_RX (2)

/* Data for SPI to transmit */
uint8_t gTxPacket1[SPI_PACKET_SIZE_TX-2] = {0x03, 0x00, 0x00}; // read package
uint8_t gTxPacket2[SPI_PACKET_SIZE_TX] = {0x02, 0x00, 0x00, 0xaa, 0xaa}; // write package

/* Data received from SPI Peripheral */
volatile uint8_t gRxPacket[SPI_PACKET_SIZE_RX];
uint8_t gRxPacketTemp[SPI_PACKET_SIZE_TX];

// OP-CODES for the MB85RS256B
uint8_t WREN = {0x06};     // 0000 0110 - Set Write Enable Latch
uint8_t WRDI = {0x04};     // 0000 0100 - Reset Write Enable Latch
uint8_t dummy = {0xFF};    // 1111 1111 - dummy byte

uint8_t msb = 0;
uint8_t lsb = 0;
uint16_t myVal = 0;

int main(void)
{
    SYSCFG_DL_init();

    DL_GPIO_clearPins(GPIO_PORT, GPIO_LED_1_PIN |
    GPIO_SEL_MUX_PIN |
    GPIO_EN_MUX_PIN);

    DL_GPIO_setPins(GPIO_PORT, GPIO_CS_SPI_PIN);

    delay_cycles(1000);

    DL_GPIO_clearPins(GPIO_PORT, GPIO_CS_SPI_PIN);

    DL_SPI_transmitDataBlocking8(SPI_0_INST, WREN);
    while (DL_SPI_isBusy(SPI_0_INST));

    DL_GPIO_setPins(GPIO_PORT, GPIO_CS_SPI_PIN);

    DL_GPIO_clearPins(GPIO_PORT, GPIO_CS_SPI_PIN);

    // DL_SPI_fillTXFIFO8(SPI_0_INST, &gTxPacket2[0], SPI_PACKET_SIZE_TX); // it works as well, why?
   
    // Maximum FIFO size is 4
    for (uint8_t i = 0; i < SPI_PACKET_SIZE_TX; i++)
    {
        while (DL_SPI_isTXFIFOFull(SPI_0_INST))
            ;
        // Put data into fifo
        DL_SPI_fillTXFIFO8(SPI_0_INST, &gTxPacket2[i], 1);
    }

    /* Wait until all bytes have been transmitted and the TX FIFO is empty */
    while (DL_SPI_isBusy(SPI_0_INST));
    gRxPacketTemp[0] = DL_SPI_receiveDataBlocking8(SPI_0_INST);

    DL_GPIO_setPins(GPIO_PORT, GPIO_CS_SPI_PIN);

    DL_GPIO_clearPins(GPIO_PORT, GPIO_CS_SPI_PIN);

    /* Fill TX FIFO with data and transmit to SPI Peripheral */
    DL_SPI_fillTXFIFO8(SPI_0_INST, &gTxPacket1[0], SPI_PACKET_SIZE_TX-2);

    /* Wait until all bytes have been transmitted and the TX FIFO is empty */
    while (DL_SPI_isBusy(SPI_0_INST));
    gRxPacketTemp[0] = DL_SPI_receiveDataBlocking8(SPI_0_INST);

    // Wait to receive the SPI data
    // This loop expects SPI_PACKET_SIZE bytes
    for (uint8_t i = 0; i < SPI_PACKET_SIZE_RX; i++) {
        DL_SPI_transmitDataBlocking8(SPI_0_INST, dummy);
        while (DL_SPI_isBusy(SPI_0_INST));
        gRxPacket[i] = DL_SPI_receiveDataBlocking8(SPI_0_INST);
    }
   
    msb = gRxPacket[0];
    lsb = gRxPacket[1];
    myVal = (msb << 8) | lsb;

    DL_GPIO_setPins(GPIO_PORT, GPIO_CS_SPI_PIN);
    
    /*DL_GPIO_clearPins(GPIO_PORT, GPIO_CS_SPI_PIN);

    DL_SPI_transmitDataBlocking8(SPI_0_INST, WRDI);
    while (DL_SPI_isBusy(SPI_0_INST));

    DL_GPIO_setPins(GPIO_PORT, GPIO_CS_SPI_PIN);*/

    /* If write and read were successful, toggle LED */
    while (1) {
        DL_GPIO_togglePins(GPIO_PORT, GPIO_LED_1_PIN);
        delay_cycles(16000000);
    }
}