求助，F28m35 can模块配置

导入例程can_loopback，这是一个外回环模式的程序，运行正常，示波器上可以观测到Tx引脚上的信号。

然后改成 SILENT模式，可以接收到Can传感器发出的信号，正常接收，Can传感器是隔一段时间自动发数据的。

但是改成Normal Mode ,我的做法是删掉这两句话
// HWREG(CAN0_BASE + CAN_O_CTL) |= CAN_CTL_TEST;
// HWREG(CAN0_BASE + CAN_O_TEST) = CAN_TEST_EXL;       

然后程序就不能运行，ES寄存器的值是0x65,芯片技术手册上说是Bit0 ERROR,如下

Bit0 Error: During the transmission of a message (or acknowledge bit, or active error flag, or
overload flag), the device wanted to send a dominant level (logical value '0'), but the monitored bus
level was recessive. During Bus-Off recovery, this status is set each time a sequence of 11
recessive bits has been monitored. This enables the CPU to monitor the proceeding of the Bus-Off
recovery sequence (indicating the bus is not stuck at dominant or continuously disturbed).

求路过的大神看看，是不是初始化哪里还有问题，个人感觉和邮箱设置无关。技术手册也看了好久，感觉初始化没问题，但是运行又不成功，对这个Bit0 error没什么办法，困扰了好多天，求大神解答，谢谢。

下面是主函数

int main(void)
{

HWREG(SYSCTL_MWRALLOW) = 0xA5A5A5A5;

// Setup main clock tree for 75MHz – M3 and 150MHz – C28x
SysCtlClockConfigSet(SYSCTL_SYSDIV_1 | SYSCTL_M3SSDIV_2 | SYSCTL_USE_PLL |
(SYSCTL_SPLLIMULT_M & 0x0F));

#ifdef _FLASH
//memcpy(&RamfuncsRunStart, &RamfuncsLoadStart, (size_t)&RamfuncsLoadSize);

FlashInit();
#endif

InitConsole();  //初始化串口

//接下来初始化  Can

//时钟 引脚配置

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);

GPIOPinConfigure(GPIO_PD0_CAN0RX);

GPIOPinConfigure(GPIO_PD1_CAN0TX);

GPIOPinTypeCAN(GPIO_PORTD_BASE, GPIO_PIN_0 | GPIO_PIN_1);

SysCtlPeripheralEnable(SYSCTL_PERIPH_CAN0);

// Initialize the CAN controller
CANInit(CAN0_BASE);

// Setup CAN to be clocked off the M3/Master subsystem clock
CANClkSourceSelect(CAN0_BASE, CAN_CLK_M3);

// Set up the bit rate for the CAN bus.
CANBitRateSet(CAN0_BASE, SysCtlClockGet(SYSTEM_CLOCK_SPEED), 500000);

// Enable interrupts on the CAN peripheral. 
CANIntEnable(CAN0_BASE, CAN_INT_MASTER | CAN_INT_ERROR | CAN_INT_STATUS);

// Register interrupt handler in RAM vector table
IntRegister(INT_CAN0INT0, CANIntHandler);

// Enable the CAN interrupt on the processor (NVIC).
IntEnable(INT_CAN0INT0);
IntMasterEnable();

// Enable test mode and select external loopback
// HWREG(CAN0_BASE + CAN_O_CTL) |= CAN_CTL_TEST;
// HWREG(CAN0_BASE + CAN_O_TEST) = CAN_TEST_EXL;          //CAN_TEST_SILENT;

// Initialize the message object that will be used for sending CAN
// messages. The message will be 8 bytes that will contain an incrementing
// value.
ucTXMsgData[0] = 0x8B;
ucTXMsgData[1] = 0xFB;
ucTXMsgData[2] = 0x00;
ucTXMsgData[3] = 0xEC;
ucTXMsgData[4] = 0x00;
ucTXMsgData[5] = 0x00;
ucTXMsgData[6] = 0x00;
ucTXMsgData[7] = 0x1D;
sTXCANMessage.ulMsgID = 0;                                                        // CAN message ID – use 1
sTXCANMessage.ulMsgIDMask = 0;                                               // no mask needed for TX
sTXCANMessage.ulFlags = MSG_OBJ_TX_INT_ENABLE;           //MSG_OBJ_TX_INT_ENABLE;
sTXCANMessage.ulMsgLen = sizeof(ucTXMsgData);                    // size of message is 8
sTXCANMessage.pucMsgData = ucTXMsgData;                           // ptr to message content

CANMessageSet(CAN0_BASE, 1, &sTXCANMessage, MSG_OBJ_TYPE_TX);

// Initialize the message object that will be used for receiving CAN
// messages.
ucRXMsgData[0] = 0x00;
ucRXMsgData[1] = 0x00;
ucRXMsgData[2] = 0x00;
ucRXMsgData[3] = 0x00;
ucRXMsgData[4] = 0x00;
ucRXMsgData[5] = 0x00;
ucRXMsgData[6] = 0x00;
ucRXMsgData[7] = 0x00;
sRXCANMessage.ulMsgID = 0x18F01D48;                                    // CAN message ID – use 1
sRXCANMessage.ulMsgIDMask = 0;                                              // no mask needed for TX
sRXCANMessage.ulFlags = MSG_OBJ_RX_INT_ENABLE;          //MSG_OBJ_RX_INT_ENABLE;
sRXCANMessage.ulMsgLen = sizeof(ucRXMsgData);                   // size of message is 8
sRXCANMessage.pucMsgData = ucRXMsgData;                          // ptr to message content

CANMessageSet(CAN0_BASE, 2, &sRXCANMessage, MSG_OBJ_TYPE_RX);

// Enable the CAN for operation.
CANEnable(CAN0_BASE);

// Enter loop to send messages. A new message will be sent once per
// second.
for(;;)
{
          // Now wait 1 second before continuing
          SimpleDelay();

          // Check the error flag to see if errors occurred
          if(g_bErrFlag)
          {
                    UARTprintf(" error – cable connected?\n");
                    UARTprintf("ulStatus : 0x%02X %02X %02X %02X\n",
                    ucCanStatus[0], ucCanStatus[1], ucCanStatus[2],
                    ucCanStatus[3]);
          }
          else
          {
                    UARTprintf("Transmit msg: 0x%02X %02X %02X %02X %02X %02X %02X %02X\n",
                    ucTXMsgData[0], ucTXMsgData[1], ucTXMsgData[2],ucTXMsgData[3],
                    ucTXMsgData[4], ucTXMsgData[5], ucTXMsgData[6],ucTXMsgData[7]);

                    UARTprintf("Receiving msg: 0x%02X %02X %02X %02X %02X %02X %02X %02X\n",
                    ucRXMsgData[0], ucRXMsgData[1], ucRXMsgData[2],ucRXMsgData[3],
                    ucRXMsgData[4], ucRXMsgData[5], ucRXMsgData[6],ucRXMsgData[7]);

                    // If no errors then print the count of message sent
                    UARTprintf(" total count = %u\n", g_ulMsgCount);
          }
}

}