有关使用stm32中spi3的问题

我在使用stm32中的spi3来驱动tlc2543的时候不成功，看了好久不知道是哪里出了问题，请大神们帮忙看看
void SPI3_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef SPI_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE );//PORTBʱÖÓʹÄÜ 
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3,ENABLE );//SPI2ʱÖÓʹÄÜ  

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;//PB3ÊÇSCLK,PB4ÊÇOUT£¬PB5ÊÇÊäÈ룬PE2-6ÊÇCS1-5
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //PB13/14/15¸´ÓÃÍÆÍìÊä³ö 
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);//³õʼ»¯GPIOB

GPIO_InitStructure.GPIO_Pin=GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);//³õʼ»¯GPIOB

GPIO_InitStructure.GPIO_Pin=GPIO_Pin_4;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING  ;  
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);//³õʼ»¯GPIOB

// GPIO_SetBits(GPIOB,GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5); //PB13/14/15ÉÏÀ­
SPI_Cmd(SPI3, DISABLE);

SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;  //ÉèÖÃSPIµ¥Ïò»òÕßË«ÏòµÄÊý¾Ýģʽ:SPIÉèÖÃΪ˫ÏßË«ÏòÈ«Ë«¹¤
SPI_InitStructure.SPI_Mode = SPI_Mode_Master;       //ÉèÖÃSPI¹¤×÷ģʽ:ÉèÖÃΪÖ÷SPI
SPI_InitStructure.SPI_DataSize = SPI_DataSize_16b;      //ÉèÖÃSPIµÄÊý¾Ý´óС:SPI·¢ËͽÓÊÕ8λ֡½á¹¹
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;      //´®ÐÐͬ²½Ê±ÖӵĿÕÏÐ״̬ΪµÍµçƽ
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;    //´®ÐÐͬ²½Ê±Öӵĵڶþ¸öÌø±äÑØ£¨ÉÏÉý»òϽµ£©Êý¾Ý±»²ÉÑù£¬cpha=0£¬
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;       //NSSÐźÅÓÉÓ²¼þ£¨NSS¹Ü½Å£©»¹ÊÇÈí¼þ£¨Ê¹ÓÃSSI룩¹ÜÀí:ÄÚ²¿NSSÐźÅÓÐSSIλ¿ØÖÆ
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;        //¶¨Ò岨ÌØÂÊÔ¤·ÖƵµÄÖµ:²¨ÌØÂÊÔ¤·ÖƵֵΪ256
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;  //Ö¸¶¨Êý¾Ý´«Êä´ÓMSBλ»¹ÊÇLSBλ¿ªÊ¼:Êý¾Ý´«Êä´ÓMSBλ¿ªÊ¼
SPI_InitStructure.SPI_CRCPolynomial = 7;    //CRCÖµ¼ÆËãµÄ¶àÏîʽ
SPI_Init(SPI3, &SPI_InitStructure);  //¸ù¾ÝSPI_InitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèSPIx¼Ä´æÆ÷

SPI_Cmd(SPI3, ENABLE); //ʹÄÜSPIÍâÉè

// SPI3_ReadWriteByte(0xff);

把JTGA给关了 默认为JTGA