你用的是四线SPI吧，怎么初始化了三条线呢，给你看看官方的例程的初始化步骤
//*****************************************************************************//// spi_master.c - Example demonstrating how to configure SSI0 in SPI master//                mode.//// Copyright (c) 2010-2014 Texas Instruments Incorporated.  All rights reserved.// Software License Agreement// //   Redistribution and use in source and binary forms, with or without//   modification, are permitted provided that the following conditions//   are met:// //   Redistributions of source code must retain the above copyright//   notice, this list of conditions and the following disclaimer.// //   Redistributions in binary form must reproduce the above copyright//   notice, this list of conditions and the following disclaimer in the//   documentation and/or other materials provided with the  //   distribution.// //   Neither the name of Texas Instruments Incorporated nor the names of//   its contributors may be used to endorse or promote products derived//   from this software without specific prior written permission.// // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.// // This is part of revision 2.1.0.12573 of the Tiva Firmware Development Package.////*****************************************************************************#include #include #include "inc/hw_memmap.h"#include "driverlib/gpio.h"#include "driverlib/pin_map.h"#include "driverlib/ssi.h"#include "driverlib/sysctl.h"#include "driverlib/uart.h"#include "utils/uartstdio.h"//*****************************************************************************////! addtogroup ssi_examples_list//!

SPI Master (spi_master)

//!//! This example shows how to configure the SSI0 as SPI Master.  The code will//! send three characters on the master Tx then polls the receive FIFO until//! 3 characters are received on the master Rx.//!//! This example uses the following peripherals and I/O signals.  You must//! review these and change as needed for your own board://! - SSI0 peripheral//! - GPIO Port A peripheral (for SSI0 pins)//! - SSI0Clk - PA2//! - SSI0Fss - PA3//! - SSI0Rx  - PA4//! - SSI0Tx  - PA5//!//! The following UART signals are configured only for displaying console//! messages for this example.  These are not required for operation of SSI0.//! - UART0 peripheral//! - GPIO Port A peripheral (for UART0 pins)//! - UART0RX - PA0//! - UART0TX - PA1//!//! This example uses the following interrupt handlers.  To use this example//! in your own application you must add these interrupt handlers to your//! vector table.//! - None.////*****************************************************************************//*****************************************************************************//// Number of bytes to send and receive.////*****************************************************************************#define NUM_SSI_DATA            3//*****************************************************************************//// This function sets up UART0 to be used for a console to display information// as the example is running.////*****************************************************************************voidInitConsole(void)[    //    // Enable GPIO port A which is used for UART0 pins.    // TODO: change this to whichever GPIO port you are using.    //    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);    //    // Configure the pin muxing for UART0 functions on port A0 and A1.    // 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_PA0_U0RX);    GPIOPinConfigure(GPIO_PA1_U0TX);    //    // Enable UART0 so that we can configure the clock.    //    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);    //    // Use the internal 16MHz oscillator as the UART clock source.    //    UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC);    //    // Select the alternate (UART) function for these pins.    // TODO: change this to select the port/pin you are using.    //    GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);    //    // Initialize the UART for console I/O.    //    UARTStdioConfig(0, 115200, 16000000);]//*****************************************************************************//// Configure SSI0 in master Freescale (SPI) mode.  This example will send out// 3 bytes of data, then wait for 3 bytes of data to come in.  This will all be// done using the polling method.////*****************************************************************************intmain(void)[    uint32_t pui32DataTx[NUM_SSI_DATA];    uint32_t pui32DataRx[NUM_SSI_DATA];    uint32_t ui32Index;    //    // Set the clocking to run directly from the external crystal/oscillator.    // TODO: The SYSCTL_XTAL_ value must be changed to match the value of the    // crystal on your board.    //    SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |                   SYSCTL_XTAL_16MHZ);    //    // Set up the serial console to use for displaying messages.  This is    // just for this example program and is not needed for SSI operation.    //    InitConsole();    //    // Display the setup on the console.    //    UARTprintf("SSI ->n");    UARTprintf("  Mode: SPIn");    UARTprintf("  Data: 8-bitnn");    //    // The SSI0 peripheral must be enabled for use.    //    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 SPI master mode.  Use SSI0,    // system clock supply, idle clock level low and active low clock in    // freescale SPI mode, master mode, 1MHz SSI frequency, and 8-bit data.    // For SPI mode, you can set the polarity of the SSI clock when the SSI    // unit is idle.  You can also configure what clock edge you want to    // capture data on.  Please reference the datasheet for more information on    // the different SPI modes.    //    SSIConfigSetExpClk(SSI0_BASE, SysCtlClockGet(), SSI_FRF_MOTO_MODE_0,                       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 SPI 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]))    [    ]    //    // Initialize the data to send.    //    pui32DataTx[0] = 's';    pui32DataTx[1] = 'p';    pui32DataTx[2] = 'i';    //    // Display indication that the SSI is transmitting data.    //    UARTprintf("Sent:n  ");    //    // Send 3 bytes of data.    //    for(ui32Index = 0; ui32Index < NUM_SSI_DATA; 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]);    ]    //    // Wait until SSI0 is done transferring all the data in the transmit FIFO.    //    while(SSIBusy(SSI0_BASE))    [    ]    //    // Display indication that the SSI is receiving data.    //    UARTprintf("nReceived:n  ");    //    // Receive 3 bytes of data.    //    for(ui32Index = 0; ui32Index < NUM_SSI_DATA; 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]);    ]    //    // Return no errors    //    return(0);]

补充下，这里的代码中用的SSI是master模式，不过基本的初始化应该是一样的。

感谢回复，我的代码配置为master时能自收发，就是将D0与在相连时能收到数据，但现在配置为slave模式
收不到数据，
从设备除了要设置SSI_MODE_MASTER为SSI_MODE_SLAVE外，还需要做哪些改动？

1.你是PC做主机呢，还是从机呢
2.你是如何测试的呢？
3.抓波形了没

感谢回复：
1. tm4c129x作为从机
2.别的设备作为主机发送数据给129x
3.抓过别的设备发送的数据
4.贴上的代码中改为master mode,将129x的ssirx与ssitx相连，能收到数据
 
我的问题是我贴的代码中要改为slave modeg还有哪些是要改的（ssi_mode我是通过抓波形设置的，而且0-3四种mode我都设置过）

我看了看，也没有什么需要修改的地方呀。
1.你主从机的线是如何连接的
2.你抓你外部的主机的数据是否已经传送出来
3.你看TM4C从机的FIFO缓冲区中是否有数据呢
4.抓全部的波形，看看是否配置正确。
还有，你配置为从模式的时候，只接收数据就好了，配置其他的应该是没用的吧。比如极性和相位。

感谢回复，代码配置没问题，是我接收数据处理有问题，目前已调通，谢谢

我就说么。希望你可以共享你从机部分的代码配置和测试代码，完善官网的代码，官方没这个例程的。

你是实现了主从自动切换吗？硬件引脚在主从切换时是否需要改动？能否共享一下代码？或者能否加QQ：317741714（317741714@qq.com）
谢谢！