TC397 CAN0_TXBRP0寄存器的TRP0一直是1，数据始终未发出的原因？

求大神指点，目前只调发送，基本配置和发送函数如下。
调用发送函数后，CAN0_TXBRP0寄存器的TRP0一直是1，数据始终未发出。
IFX_CONST IfxCan_Can_Pins can_pins[CAN_NUM] = {
    { IfxCan_TXD00_P20_8_OUT, IfxPort_OutputMode_pushPull, // Tx pin
     IfxCan_RXD00B_P20_7_IN, IfxPort_InputMode_pullUp, // Rx pin
    IfxPort_PadDriver_cmosAutomotiveSpeed4},
    ......
};
void can_init(int index) {
// create module configuration
    IfxCan_Can_Config canConfig;
    IfxCan_Can can;
    IfxCan_NodeId can_node_num = 0;
    IfxCan_Can_initModuleConfig( canConfig,  MODULE_CAN0);
// initialize module
    IfxCan_Can_initModule( can,  canConfig);
    can_node_num = index % 4;
    // create node configuration
    {
       IfxCan_Can_initNodeConfig( g_drv_can[index].can_node_config,  can);
       // initialize Node 0 g_drv_can[index].can_node_config.nodeId = can_node_num;
       g_drv_can[index].can_node_config.clockSource = IfxCan_ClockSource_both;
         g_drv_can[index].can_node_config.frame.type = IfxCan_FrameType_transmitAndReceive;
        g_drv_can[index].can_node_config.frame.mode = IfxCan_FrameMode_fdLong;
        g_drv_can[index].can_node_config.txConfig.dedicatedTxBuffersNumber = 31;
        g_drv_can[index].can_node_config.txConfig.txMode = IfxCan_TxMode_dedicatedBuffers;
        g_drv_can[index].can_node_config.txConfig.txBufferDataFieldSize = IfxCan_DataFieldSize_8;

       g_drv_can[index].can_node_config.messageRAM.txBuffersStartAddress = 0x400;
        g_drv_can[index].can_node_config.messageRAM.baseAddress = MODULE_CAN0_RAM + NODE0_RAM_OFFSET;
        g_drv_can[index].can_node_config.baudRate.baudrate = 500000;
        g_drv_can[index].can_node_config.pins =  can_pins[index];
       g_drv_can[index].can_node_config.busLoopbackEnabled = FALSE;
        g_drv_can[index].can_node_config.calculateBitTimingValues = TRUE;
       // initialize Node 0
       IfxCan_Can_initNode( g_drv_can[index].can_node,  g_drv_can[index].can_node_config);
}
}
void can_send(int index)
{
IfxCan_Can_initMessage( g_drv_can[index].tx_msg);
// change the relevent members of message structure
g_drv_can[index].tx_msg.bufferNumber = 0;
g_drv_can[index].tx_msg.dataLengthCode = IfxCan_DataLengthCode_8;
g_drv_can[index].tx_msg.frameMode = IfxCan_FrameMode_fdLong;
g_drv_can[index].tx_msg.messageIdLength = IfxCan_MessageIdLength_standard;
g_drv_can[index].tx_msg.messageId = CAN_MESSAGE_ID;
g_drv_can[index].txdata[0] = 0x78563412;
g_drv_can[index].txdata[1] = 0xf0debc9a;
// Transmit Data
IfxCan_Can_sendMessage( g_drv_can[index].can_node,  g_drv_can[index].tx_msg, g_drv_can[index].txdata);
}