TMS570LC4357: How to change DLC when sending,

NA GAO

Part Number: TMS570LC4357

How to change DLC when sending,如何发送可变字节长度的报文

I modified the DLC value in the cantransmit function, but it still failed. 我在canTransmit函数中修改DLC的值但还是不行

有没有参考的流程，手册我已经看了很多次了还是不太明白。

2 年多前

0 Green Deng 2 年多前

TI__Guru** 101655 points

你好，问题已经收到，我需要向其他工程师咨询一下之后再回复你，还请耐心等待。

0 NA GAO 2 年多前回复 Green Deng

谢谢

0 NA GAO 2 年多前

我也想知道如何读取接收到报文的DLC值

0 Green Deng 2 年多前回复 NA GAO

TI__Guru** 101655 points

可以在将数据从 IFx 寄存器传输到 DCAN 消息 RAM 或邮箱之前更新 DLC。 HAL 代码没有更新 DLC 的 API，但可以编写自己的 API。例如：

void canUpdateDLC(canBASE_t *node, uint32 messageBox, uint8 msgBoxDLC)
{

       /** - Wait until IF2 is ready for use */
      while ((node->IF2STAT & 0x80U) ==0x80U)
      {
      } /* Wait */

      node->IF2CMD = 0x90U;

      node->IF2MCTL &= ~(uint32)(0xFU);

      node->IF2MCTL |= (uint32)(msgBoxDLC & 0xFU);

      node->IF2NO = (uint8) messageBox;

      /** - Wait until data are copied into IF2 */
      while ((node->IF2STAT & 0x80U) ==0x80U)
      {
      } /* Wait */

}

消息对象的DLC必须定义为与其他节点具有相同标识符的相应对象中的值相同。

0 NA GAO 2 年多前回复 Green Deng

//可以把这个程序添加在Transmit函数里面吗？

uint32 canTransmit(canBASE_t *node, uint32 messageBox, const uint8 * data,uint8 msgBoxDLC)
{
uint32 i;
uint32 success = 0U;
uint32 regIndex = (messageBox - 1U) >> 5U;
uint32 bitIndex = 1U << ((messageBox - 1U) & 0x1FU);

/* USER CODE BEGIN (7) */ //添加在这里

/** - Wait until IF2 is ready for use */
while ((node->IF2STAT & 0x80U) ==0x80U)
{
} /* Wait */

node->IF2CMD = 0x90U;

node->IF2MCTL &= ~(uint32)(0xFU);

node->IF2MCTL |= (uint32)(msgBoxDLC & 0xFU);

node->IF2NO = (uint8) messageBox;

/** - Wait until data are copied into IF2 */
while ((node->IF2STAT & 0x80U) ==0x80U)
{
} /* Wait */

/* USER CODE END */

/** - Check for pending message:
* - pending message, return 0
* - no pending message, start new transmission
*/

if ((node->TXRQx[regIndex] & bitIndex) != 0U)
{
success = 0U;
}

else
{
/** - Wait until IF1 is ready for use */
/*SAFETYMCUSW 28 D MR:NA <APPROVED> "Potentially infinite loop found - Hardware Status check for execution sequence" */
while ((node->IF1STAT & 0x80U) ==0x80U)
{
} /* Wait */

/** - Configure IF1 for
* - Message direction - Write
* - Data Update
* - Start Transmission
*/
/*SAFETYMCUSW 28 D MR:NA <APPROVED> "Potentially infinite loop found - Hardware Status check for execution sequence" */

/** - Copy TX data into IF1 */
for (i = 0U; i < msgBoxDLC; i++) //这里循环条件改成DLC
{
#if ((__little_endian__ == 1) || (__LITTLE_ENDIAN__ == 1))
/*SAFETYMCUSW 45 D MR:21.1 <APPROVED> "Valid non NULL input parameters are only allowed in this driver" */
node->IF1DATx[i] = *data;
/*SAFETYMCUSW 45 D MR:21.1 <APPROVED> "Valid non NULL input parameters are only allowed in this driver" */
data++;
#else
/*SAFETYMCUSW 45 D MR:21.1 <APPROVED> "Valid non NULL input parameters are only allowed in this driver" */
node->IF1DATx[s_canByteOrder[i]] = *data;
/*SAFETYMCUSW 45 D MR:21.1 <APPROVED> "Valid non NULL input parameters are only allowed in this driver" */
data++;
#endif
}

/** - Copy TX data into message box */
/*SAFETYMCUSW 93 S MR: 6.1,6.2,10.1,10.2,10.3,10.4 <APPROVED> "LDRA Tool issue" */
node->IF1NO = (uint8) messageBox;

success = 1U;
}
/** @note The function canInit has to be called before this function can be used.\n
* The user is responsible to initialize the message box.
*/

/* USER CODE BEGIN (8) */
/* USER CODE END */

return success;
}

0 NA GAO 2 年多前回复 Green Deng

接收到的报文怎么读取DLC

0 Green Deng 2 年多前回复 NA GAO

TI__Guru** 101655 points

收到，我会尽快帮你反馈。

0 NA GAO 2 年多前回复 Green Deng

使用canUpdateID函数更新ID后，发送的数据帧变成远程帧了，我不知道原因

0 Green Deng 2 年多前回复 NA GAO

TI__Guru** 101655 points

这是新问题？新问题的话还请麻烦新开一个帖子，都放一起会乱

0 NA GAO 2 年多前回复 Green Deng

谢谢

0 Green Deng 2 年多前回复 NA GAO

TI__Guru** 101655 points

客气了，之前的问题应该会在明天回复你。

+1 Green Deng 2 年多前回复 NA GAO

TI__Guru** 101655 points

1、是的，可以将新 ID、DLC 添加到传输 API。

NA GAO 说：
/** - Copy TX data into IF1 */
for (i = 0U; i < msgBoxDLC; i++) //这里循环条件改成DLC

这里不必将 8 更改为 msgBoxDLC。无论 DLC 有多小，八字节数据都会从 IFx 数据寄存器（A 和 B）传输到消息 RAM。

2、DLC 是消息控制寄存器的一部分。您需要设置 CMD 寄存器的 CONTROL 位和 CMD 寄存器的 CLEAR W/R 位，以便将 DLC 从 Message RAM 传输到 Fx 寄存器：

canGetData(0 API include this portion:

/** - Configure IF2 for
* - Message direction - Read
* - Data Read
* - Clears NewDat bit in the message object.
*/
node->IF2CMD = 0x17U;

/** - Copy data into IF2 */
/*SAFETYMCUSW 93 S MR: 6.1,6.2,10.1,10.2,10.3,10.4 <APPROVED> "LDRA Tool issue" */
node->IF2NO = (uint8) messageBox;

/** - Wait until data are copied into IF2 */
/*SAFETYMCUSW 28 D MR:NA <APPROVED> "Potentially infinite loop found - Hardware Status check for execution sequence" */
while ((node->IF2STAT & 0x80U) ==0x80U)
{
} /* Wait */

/** - Get number of received bytes */
size = node->IF2MCTL & 0xFU;
if(size > 0x8U)
{
size = 0x8U;
}
/** - Copy RX data into destination buffer */

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TMS570LC4357: How to change DLC when sending,