两块arm板板件spi通信实例

1.我用的两块板子都是tm4c123gxl ,cortex M4内核。两块板子一块用作主设备，一块用作从设备。连接时，主从设备的 sck，fss对应相连。主设备tx接从设备rx。

主设备代码如下：

//*****************************************************************************
//
//*****************************************************************************

#include 
#include 
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/fpu.h"
#include "driverlib/ssi.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"
#include "utils/uartstdio.h"


#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif

#define NUM_SSI_DATA            3

//*****************************************************************************
//
// Configure the UART and its pins.  This must be called before UARTprintf().
//
//*****************************************************************************
void
ConfigureUART(void)
{
    //
    // Enable the GPIO Peripheral used by the UART.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

    //
    // Enable UART0
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);

    //
    // Configure GPIO Pins for UART mode.
    //
    GPIOPinConfigure(GPIO_PA0_U0RX);
    GPIOPinConfigure(GPIO_PA1_U0TX);
    GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);

    //
    // Use the internal 16MHz oscillator as the UART clock source.
    //
    UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC);

    //
    // Initialize the UART for console I/O.
    //
    UARTStdioConfig(0, 115200, 16000000);
}

//*****************************************************************************
//
// Print "Hello World!" to the UART on the evaluation board.
//
//*****************************************************************************
int
main(void)
{
    //volatile uint32_t ui32Loop;

    //
	  uint32_t pui32DataTx[NUM_SSI_DATA];
    uint32_t pui32DataRx[NUM_SSI_DATA];
    uint32_t ui32Index;

	
	
	
    // Enable lazy stacking for interrupt handlers.  This allows floating-point
    // instructions to be used within interrupt handlers, but at the expense of
    // extra stack usage.
    //
    FPULazyStackingEnable();

    //
    // Set the clocking to run directly from the crystal.
    //
    SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ |
                       SYSCTL_OSC_MAIN);

    //
    // Enable the GPIO port that is used for the on-board LED.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);

    //
    // Enable the GPIO pins for the LED (PF2 & PF3).
    //
    GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_2);

     


    //
    // Initialize the UART.
    //
      ConfigureUART();


    SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI0);

    //
    // For this example SSI0 is used with PortA[5:2].  The actual port and
    // pins used may be different on your part, consult the data sheet for
    // more information.  GPIO port A needs to be enabled so these pins can
    // be used.
    // TODO: change this to whichever GPIO port you are using.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

    //
    // Configure the pin muxing for SSI0 functions on port A2, A3, A4, and A5.
    // This step is not necessary if your part does not support pin muxing.
    // TODO: change this to select the port/pin you are using.
    //
    GPIOPinConfigure(GPIO_PA2_SSI0CLK);
    GPIOPinConfigure(GPIO_PA3_SSI0FSS);
    GPIOPinConfigure(GPIO_PA4_SSI0RX);
    GPIOPinConfigure(GPIO_PA5_SSI0TX);

    //
    // Configure the GPIO settings for the SSI pins.  This function also gives
    // control of these pins to the SSI hardware.  Consult the data sheet to
    // see which functions are allocated per pin.
    // The pins are assigned as follows:
    //      PA5 - SSI0Tx
    //      PA4 - SSI0Rx
    //      PA3 - SSI0Fss
    //      PA2 - SSI0CLK
    // TODO: change this to select the port/pin you are using.
    //
    GPIOPinTypeSSI(GPIO_PORTA_BASE, GPIO_PIN_5 | GPIO_PIN_4 | GPIO_PIN_3 |
                   GPIO_PIN_2);

    //
    // Configure and enable the SSI port for TI master mode.  Use SSI0, system
    // clock supply, master mode, 1MHz SSI frequency, and 8-bit data.
    //
    SSIConfigSetExpClk(SSI0_BASE, SysCtlClockGet(), SSI_FRF_TI,
                       SSI_MODE_MASTER, 1000000, 8);

    //
    // Enable the SSI0 module.
    //
    SSIEnable(SSI0_BASE);

    //
    // Read any residual data from the SSI port.  This makes sure the receive
    // FIFOs are empty, so we don't read any unwanted junk.  This is done here
    // because the TI SSI mode is full-duplex, which allows you to send and
    // receive at the same time.  The SSIDataGetNonBlocking function returns
    // "true" when data was returned, and "false" when no data was returned.
    // The "non-blocking" function checks if there is any data in the receive
    // FIFO and does not "hang" if there isn't.
    //
    while(SSIDataGetNonBlocking(SSI0_BASE, &pui32DataRx[0]))
    {
    }
    UARTprintf("......................\n\n");
    //
    // Initialize the data to send.
    //
    pui32DataTx[0] = 'n';
    pui32DataTx[1] = 'm';
    pui32DataTx[2] = 'b';

    //
    // Display indication that the SSI is transmitting data.
    //
   UARTprintf("Sent:\n  ");

    //
    // Send 3 bytes of data.
    //
    for(ui32Index = 0; ui32Index     {
        //
        // Display the data that SSI is transferring.
        //
        UARTprintf("'%c' ", pui32DataTx[ui32Index]);

        //
        // Send the data using the "blocking" put function.  This function
        // will wait until there is room in the send FIFO before returning.
        // This allows you to assure that all the data you send makes it into
        // the send FIFO.
        //
        SSIDataPut(SSI0_BASE, pui32DataTx[ui32Index]);
    }     
      UARTprintf("\nSend Success!\n  ");              
           
    // 
    while(1)
    {
        //
        // Turn on the BLUE LED.
        //
        GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, GPIO_PIN_2);

        //
        // Delay for a bit.
        //
        SysCtlDelay(SysCtlClockGet() / 10 / 3);

        //
        // Turn off the BLUE LED.
        //
        GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, 0);                 

        //
        // Delay for a bit.
        //
        SysCtlDelay(SysCtlClockGet() / 10 / 3);
    }   
}

从设备上代码：

//*****************************************************************************
//
//*****************************************************************************

#include 
#include 
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/fpu.h"
#include "driverlib/ssi.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"
#include "utils/uartstdio.h"


#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif

#define NUM_SSI_DATA            3

//*****************************************************************************
//
// Configure the UART and its pins.  This must be called before UARTprintf().
//
//*****************************************************************************
void
ConfigureUART(void)
{
    //
    // Enable the GPIO Peripheral used by the UART.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

    //
    // Enable UART0
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);

    //
    // Configure GPIO Pins for UART mode.
    //
    GPIOPinConfigure(GPIO_PA0_U0RX);
    GPIOPinConfigure(GPIO_PA1_U0TX);
    GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);

    //
    // Use the internal 16MHz oscillator as the UART clock source.
    //
    UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC);

    //
    // Initialize the UART for console I/O.
    //
    UARTStdioConfig(0, 115200, 16000000);
}

//*****************************************************************************
//
// Print "Hello World!" to the UART on the evaluation board.
//
//*****************************************************************************
int
main(void)
{
    //volatile uint32_t ui32Loop;

    //
	  uint32_t pui32DataTx[NUM_SSI_DATA];
    uint32_t pui32DataRx[NUM_SSI_DATA];
    uint32_t ui32Index;

	
	
	
    // Enable lazy stacking for interrupt handlers.  This allows floating-point
    // instructions to be used within interrupt handlers, but at the expense of
    // extra stack usage.
    //
    FPULazyStackingEnable();

    //
    // Set the clocking to run directly from the crystal.
    //
    SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ |
                       SYSCTL_OSC_MAIN);

    //
    // Enable the GPIO port that is used for the on-board LED.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);

    //
    // Enable the GPIO pins for the LED (PF2 & PF3).
    //
    GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_2);

     


    //
    // Initialize the UART.
    //
      ConfigureUART();


    SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI0);

    //
    // For this example SSI0 is used with PortA[5:2].  The actual port and
    // pins used may be different on your part, consult the data sheet for
    // more information.  GPIO port A needs to be enabled so these pins can
    // be used.
    // TODO: change this to whichever GPIO port you are using.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

    //
    // Configure the pin muxing for SSI0 functions on port A2, A3, A4, and A5.
    // This step is not necessary if your part does not support pin muxing.
    // TODO: change this to select the port/pin you are using.
    //
    GPIOPinConfigure(GPIO_PA2_SSI0CLK);
    GPIOPinConfigure(GPIO_PA3_SSI0FSS);
    GPIOPinConfigure(GPIO_PA4_SSI0RX);
    GPIOPinConfigure(GPIO_PA5_SSI0TX);

    //
    // Configure the GPIO settings for the SSI pins.  This function also gives
    // control of these pins to the SSI hardware.  Consult the data sheet to
    // see which functions are allocated per pin.
    // The pins are assigned as follows:
    //      PA5 - SSI0Tx
    //      PA4 - SSI0Rx
    //      PA3 - SSI0Fss
    //      PA2 - SSI0CLK
    // TODO: change this to select the port/pin you are using.
    //
    GPIOPinTypeSSI(GPIO_PORTA_BASE, GPIO_PIN_5 | GPIO_PIN_4 | GPIO_PIN_3 |
                   GPIO_PIN_2);

    //
    // Configure and enable the SSI port for TI master mode.  Use SSI0, system
    // clock supply, master mode, 1MHz SSI frequency, and 8-bit data.
    //
    SSIConfigSetExpClk(SSI0_BASE, SysCtlClockGet(), SSI_FRF_TI,
                       SSI_MODE_SLAVE, 1000000, 8);

    //
    // Enable the SSI0 module.
    //
    SSIEnable(SSI0_BASE);

    //
    // Read any residual data from the SSI port.  This makes sure the receive
    // FIFOs are empty, so we don't read any unwanted junk.  This is done here
    // because the TI SSI mode is full-duplex, which allows you to send and
    // receive at the same time.  The SSIDataGetNonBlocking function returns
    // "true" when data was returned, and "false" when no data was returned.
    // The "non-blocking" function checks if there is any data in the receive
    // FIFO and does not "hang" if there isn't.
    //
    while(SSIDataGetNonBlocking(SSI0_BASE, &pui32DataRx[0]))
    {
    }
    UARTprintf("......................\n\n");

		UARTprintf("\nRead:\n  ");

    while(SSIBusy(SSI0_BASE))
    {
    }
   
    //
    // Display indication that the SSI is receiving data.
    //
    //UARTprintf("\nReceived:\n  ");

    //
    // Receive 3 bytes of data.
    //
    for(ui32Index = 0; ui32Index     {
        //
        // Receive the data using the "blocking" Get function. This function
        // will wait until there is data in the receive FIFO before returning.
        //
        SSIDataGet(SSI0_BASE, &pui32DataRx[ui32Index]);

        //
        // Since we are using 8-bit data, mask off the MSB.
        //
        pui32DataRx[ui32Index] &= 0x00FF;

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

 


    while(1)
    {
        //
        // Turn on the BLUE LED.
        //
        GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, GPIO_PIN_2);

        //
        // Delay for a bit.
        //
        SysCtlDelay(SysCtlClockGet() / 10 / 3);

        //
        // Turn off the BLUE LED.
        //
        GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, 0);                 

        //
        // Delay for a bit.
        //
        SysCtlDelay(SysCtlClockGet() / 10 / 3);
    }   
}

             FSS：      PA3

             RX：        PA4

             TX：         PA5

效果图：