MSP432 SPI3线调试不成功

只看该作者 · 2017-6-12 21:02

在研究432的SPI时，先用的官网3线的收发例程。用的432A1做主机，B1做从机，连了个时钟，MISO和MOSI3根线，程序如下：

#include "msp.h"
#include "driverlib/driverlib.h"

static uint8_t TXData = 0;
static volatile uint8_t RXData = 0;
static volatile uint8_t transmitData = 0x87, receiveData = 0x00;

const eUSCI_SPI_MasterConfig spiMasterConfig =
{
EUSCI_A_SPI_CLOCKSOURCE_SMCLK, // SMCLK Clock Source
3000000, // SMCLK = DCO = 3MHZ
3000000, // SPICLK = 500khz
EUSCI_A_SPI_MSB_FIRST, // MSB First
EUSCI_A_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT,
EUSCI_A_SPI_CLOCKPOLARITY_INACTIVITY_HIGH,
EUSCI_SPI_3PIN
};

const eUSCI_SPI_SlaveConfig spiSlaveConfig =
{
EUSCI_B_SPI_MSB_FIRST, // MSB First
EUSCI_B_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT, // Phase
EUSCI_B_SPI_CLOCKPOLARITY_INACTIVITY_HIGH, // Normal Polarity
EUSCI_SPI_3PIN
};

void main(void)
{
uint8_t aa=0,aaa=0;
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer
//主机设置
GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P2,
GPIO_PIN0 | GPIO_PIN1 | GPIO_PIN2 | GPIO_PIN3, GPIO_PRIMARY_MODULE_FUNCTION);
//从机设置
GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P6,
GPIO_PIN2 | GPIO_PIN3 | GPIO_PIN4 | GPIO_PIN5, GPIO_PRIMARY_MODULE_FUNCTION);
SPI_initMaster(EUSCI_A1_BASE, &spiMasterConfig);
SPI_initSlave(EUSCI_B1_BASE, &spiSlaveConfig);
SPI_enableModule(EUSCI_A1_BASE);
SPI_enableModule(EUSCI_B1_BASE);

SPI_enableInterrupt(EUSCI_B1_BASE, EUSCI_B_SPI_RECEIVE_INTERRUPT);
Interrupt_enableInterrupt(INT_EUSCIB1);
Interrupt_enableMaster();

TXData = 0x53;
while (!(SPI_getInterruptStatus(EUSCI_A1_BASE,EUSCI_A_SPI_TRANSMIT_INTERRUPT)));
SPI_transmitData(EUSCI_A1_BASE, TXData++);

while (!(SPI_getInterruptStatus(EUSCI_A1_BASE,EUSCI_A_SPI_RECEIVE_INTERRUPT)));
aa=SPI_receiveData(EUSCI_A1_BASE);

while (!(SPI_getInterruptStatus(EUSCI_A1_BASE,EUSCI_A_SPI_TRANSMIT_INTERRUPT)));
SPI_transmitData(EUSCI_A1_BASE, TXData);

while (!(SPI_getInterruptStatus(EUSCI_A1_BASE,EUSCI_A_SPI_RECEIVE_INTERRUPT)));
aaa=SPI_receiveData(EUSCI_A1_BASE);

while(1);
}

void EUSCIB1_IRQHandler(void)
{
uint32_t status;

status = SPI_getEnabledInterruptStatus(EUSCI_B1_BASE);
SPI_clearInterruptFlag(EUSCI_B1_BASE, status);

if(status & EUSCI_B_SPI_RECEIVE_INTERRUPT)
{
/* USCI_B1 TX buffer ready? */
while (!(SPI_getInterruptStatus(EUSCI_B1_BASE, EUSCI_B_SPI_TRANSMIT_INTERRUPT)));

/* Transmit data to master */
SPI_transmitData(EUSCI_B1_BASE, transmitData++);

//Receive data from master
receiveData = SPI_receiveData(EUSCI_B1_BASE);
}
}

中间绿色那段是我测试的收发段，我的意图是主机发送一个字节，然后从机收到，进入从机接收中断；然后从机再给主机发送一个字节，主机收到。然后再循环一次。但是问题出现在第一次从中断返回的时候，进从机中断的时候可以收到主机发来的数据，但是在中断里由从机给主机发数据的时候，从机TXbuffer显示有发送，但是主机RXbuffer没有数据，然后aa赋值就为0（图1）。但是第二次进中断的时候，主机接收有了从机第一次发送的值（图2）（这个是延时吗？但是我等一好久，主机接收始终没有收到从机发送的第二个值，第二次的值应该是0x88）。