STM32F4 HAL库的三个发送邮箱处理方法
框图：
HAL库的处理，库本身做的处理：
/**
* @briefAdd a message to the first free Tx mailbox and activate the
* corresponding transmission request.
* @paramhcan pointer to a CAN_HandleTypeDef structure that contains
* the configuration information for the specified CAN.
* @parampHeader pointer to a CAN_TxHeaderTypeDef structure.
* @paramaData array containing the payload of the Tx frame.
* @parampTxMailbox pointer to a variable where the function will return
* the TxMailbox used to store the Tx message.
* This parameter can be a value of @arg CAN_Tx_Mailboxes.
* @retval HAL status
*/
HAL_StatusTypeDef HAL_CAN_AddTxMessage(CAN_HandleTypeDef *hcan, CAN_TxHeaderTypeDef *pHeader, uint8_t aData[], uint32_t *pTxMailbox)
{
uint32_t transmitmailbox;
HAL_CAN_StateTypeDef state = hcan->State;
uint32_t tsr = READ_REG(hcan->Instance->TSR);
/* Check the parameters */
assert_param(IS_CAN_IDTYPE(pHeader->IDE));
assert_param(IS_CAN_RTR(pHeader->RTR));
assert_param(IS_CAN_DLC(pHeader->DLC));
if (pHeader->IDE == CAN_ID_STD)
{
assert_param(IS_CAN_STDID(pHeader->StdId));
}
else
{
assert_param(IS_CAN_EXTID(pHeader->ExtId));
}
assert_param(IS_FUNCTIONAL_STATE(pHeader->TransmitGlobalTime));
if ((state == HAL_CAN_STATE_READY) ||
(state == HAL_CAN_STATE_LISTENING))
{
/* Check that all the Tx mailboxes are not full */
if (((tsr & CAN_TSR_TME0) != 0U) ||
((tsr & CAN_TSR_TME1) != 0U) ||
((tsr & CAN_TSR_TME2) != 0U))
{
/* Select an empty transmit mailbox */
transmitmailbox = (tsr & CAN_TSR_CODE) >> CAN_TSR_CODE_Pos;
/* Check transmit mailbox value */
if (transmitmailbox > 2U)
{
/* Update error code */
hcan->ErrorCode |= HAL_CAN_ERROR_INTERNAL;
return HAL_ERROR;
}
/* Store the Tx mailbox */
*pTxMailbox = (uint32_t)1 << transmitmailbox;
/* Set up the Id */
if (pHeader->IDE == CAN_ID_STD)
{
hcan->Instance->sTxMailBox.TIR = ((pHeader->StdId << CAN_TI0R_STID_Pos) |
pHeader->RTR);
}
else
{
hcan->Instance->sTxMailBox.TIR = ((pHeader->ExtId << CAN_TI0R_EXID_Pos) |
pHeader->IDE |
pHeader->RTR);
}
/* Set up the DLC */
hcan->Instance->sTxMailBox.TDTR = (pHeader->DLC);
/* Set up the Transmit Global Time mode */
if (pHeader->TransmitGlobalTime == ENABLE)
{
SET_BIT(hcan->Instance->sTxMailBox.TDTR, CAN_TDT0R_TGT);
}
/* Set up the data field */
WRITE_REG(hcan->Instance->sTxMailBox.TDHR,
((uint32_t)aData << CAN_TDH0R_DATA7_Pos) |
((uint32_t)aData << CAN_TDH0R_DATA6_Pos) |
((uint32_t)aData << CAN_TDH0R_DATA5_Pos) |
((uint32_t)aData << CAN_TDH0R_DATA4_Pos));
WRITE_REG(hcan->Instance->sTxMailBox.TDLR,
((uint32_t)aData << CAN_TDL0R_DATA3_Pos) |
((uint32_t)aData << CAN_TDL0R_DATA2_Pos) |
((uint32_t)aData << CAN_TDL0R_DATA1_Pos) |
((uint32_t)aData << CAN_TDL0R_DATA0_Pos));
/* Request transmission */
SET_BIT(hcan->Instance->sTxMailBox.TIR, CAN_TI0R_TXRQ);
/* Return function status */
return HAL_OK;
}
else
{
/* Update error code */
hcan->ErrorCode |= HAL_CAN_ERROR_PARAM;
return HAL_ERROR;
}
}
else
{
/* Update error code */
hcan->ErrorCode |= HAL_CAN_ERROR_NOT_INITIALIZED;
return HAL_ERROR;
}
}
这一段代码怎么用？ Y1ng 发表于 2024-1-14 19:26
这一段代码怎么用？
直接调用就行，HAL库的这个API自动从里面选择选择可用的发送邮箱了。
基于STM32F429的HAL版双CAN通信案例（2023-10-24）
https://www.armbbs.cn/forum.php?mod=viewthread&tid=121523&fromuid=58
(出处: 硬汉嵌入式论坛)
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