STM32F205 CAN通信问题【悬赏问答】

uniqueeefocus34 提问时间：2012-10-17 18:55 /

用的stm32f2xx_stdperiph_lib里的示例程序做CAN通信测试，环回模式测试OK。正常模式下，用CAN调试软件向板子发数据，始终进不了接收中断
.c文件
int main(void)
{

/* NVIC configuration */
NVIC_Config();

/* CAN configuration */
CAN_Config();

/* Infinite loop */
while(1)
{
        Delay();
}
}

void CAN_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;

/* CAN GPIOs configuration **************************************************/

/* Enable GPIO clock */
RCC_AHB1PeriphClockCmd(CAN_GPIO_CLK, ENABLE);

GPIO_PinAFConfig(CAN_GPIO_PORT, CAN_RX_SOURCE, CAN_AF_PORT);
GPIO_PinAFConfig(CAN_GPIO_PORT, CAN_TX_SOURCE, CAN_AF_PORT);

/* Configure CAN RX and TX pins */
GPIO_InitStructure.GPIO_Pin = CAN_RX_PIN | CAN_TX_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(CAN_GPIO_PORT, &GPIO_InitStructure);

/* CAN configuration ********************************************************/
/* Enable CAN clock */
RCC_APB1PeriphClockCmd(CAN_CLK, ENABLE);

/* CAN register init */
CAN_DeInit(CANx);

/* CAN cell init */
CAN_InitStructure.CAN_TTCM = DISABLE;
CAN_InitStructure.CAN_ABOM = DISABLE;
CAN_InitStructure.CAN_AWUM = DISABLE;
CAN_InitStructure.CAN_NART = DISABLE;
CAN_InitStructure.CAN_RFLM = DISABLE;
CAN_InitStructure.CAN_TXFP = DISABLE;
CAN_InitStructure.CAN_Mode = CAN_Mode_Normal;
CAN_InitStructure.CAN_SJW = CAN_SJW_1tq;

/* CAN Baudrate = 1MBps (CAN clocked at 30 MHz) */
/*CAN_InitStructure.CAN_BS1 = CAN_BS1_6tq;
CAN_InitStructure.CAN_BS2 = CAN_BS2_8tq;
CAN_InitStructure.CAN_Prescaler = 2;
CAN_Init(CANx, &CAN_InitStructure);*/

/* CAN filter init */
#ifdef USE_CAN1
CAN_FilterInitStructure.CAN_FilterNumber = 0;
#else /* USE_CAN2 */
CAN_FilterInitStructure.CAN_FilterNumber = 14;
#endif /* USE_CAN1 */
CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask;
CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_32bit;
CAN_FilterInitStructure.CAN_FilterIdHigh = 0x0000;
CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;
CAN_FilterInitStructure.CAN_FilterFIFOAssignment = 0;
CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;
CAN_FilterInit(&CAN_FilterInitStructure);

/* Enable FIFO 0 message pending Interrupt */
CAN_ITConfig(CANx, CAN_IT_FMP0, ENABLE);
}

void NVIC_Config(void)
{
NVIC_InitTypeDef NVIC_InitStructure;

#ifdef USE_CAN1
NVIC_InitStructure.NVIC_IRQChannel = CAN1_RX0_IRQn;
#else /* USE_CAN2 */
NVIC_InitStructure.NVIC_IRQChannel = CAN2_RX0_IRQn;
#endif /* USE_CAN1 */

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

.h头文件
#define USE_CAN1
//#define USE_CAN2

#ifdef USE_CAN1
#define CANx                       CAN1
#define CAN_CLK                    RCC_APB1Periph_CAN1
#define CAN_RX_PIN                 GPIO_Pin_11
#define CAN_TX_PIN                 GPIO_Pin_12
#define CAN_GPIO_PORT              GPIOA
#define CAN_GPIO_CLK               RCC_AHB1Periph_GPIOA
#define CAN_AF_PORT                GPIO_AF_CAN1
#define CAN_RX_SOURCE              GPIO_PinSource11
#define CAN_TX_SOURCE              GPIO_PinSource12
#else /*USE_CAN2*/
#define CANx                       CAN2
#define CAN_CLK                    (RCC_APB1Periph_CAN1 | RCC_APB1Periph_CAN2)
#define CAN_RX_PIN                 GPIO_Pin_12
#define CAN_TX_PIN                 GPIO_Pin_13
#define CAN_GPIO_PORT              GPIOB
#define CAN_GPIO_CLK               RCC_AHB1Periph_GPIOB
#define CAN_AF_PORT                GPIO_AF_CAN2
#define CAN_RX_SOURCE              GPIO_PinSource12
#define CAN_TX_SOURCE              GPIO_PinSource13
#endif /* USE_CAN1 */

stm32f2xx_it.c 文件中涉及的CAN接收中断程序
#ifdef USE_CAN1
void CAN1_RX0_IRQHandler(void)
{
CAN_Receive(CAN1, CAN_FIFO0, &RxMessage);
   CAN_FIFORelease(CAN2, CAN_FIFO0);
}
#endif /* USE_CAN1 */

#ifdef USE_CAN2
/**
* @brief This function handles CAN2 RX0 request.
* @param None
* @retval None
*/
void CAN2_RX0_IRQHandler(void)
{
CAN_Receive(CAN2, CAN_FIFO0, &RxMessage);
    CAN_FIFORelease(CAN2, CAN_FIFO0);
}
#endif /* USE_CAN2 */

以上，PC端通过USB-CAN-A2设备与板子连接，CAN调试工具不断发数据。用示波器测收发器的CANH及CANL脚，有脉冲波形，说明CAN口能正常接收到PC端数据。但测收发器的RX脚(RX脚连MCU引出的PA11脚，复用为CAN_RX功能)始终为高电平，没有收到有效信号。