我們看 CanRxMsg

typedef struct
{
? uint32_t StdId;? /* Specifies the standard identifier.
????????????????????? This parameter can be a value between 0 to 0x7FF. */

? uint32_t ExtId;? /* Specifies the extended identifier.
????????????????????? This parameter can be a value between 0 to 0x1FFFFFFF. */

? uint8_t IDE;???? /* Specifies the type of identifier for the message that
????????????????????? will be received. This parameter can be a value of
????????????????????? @ref CAN_identifier_type */

? uint8_t RTR;???? /* Specifies the type of frame for the received message.
????????????????????? This parameter can be a value of
????????????????????? @ref CAN_remote_transmission_request */

? uint8_t DLC;???? /* Specifies the length of the frame that will be received.
????????????????????? This parameter can be a value between 0 to 8 */

? uint8_t Data[8]; /* Contains the data to be received. It ranges from 0 to
????????????????????? 0xFF. */

? uint8_t FMI;???? /* Specifies the index of the filter the message stored in
????????????????????? the mailbox passes through. This parameter can be a
????????????????????? value between 0 to 0xFF */
} CanRxMsg;

Data字段作為一個 uint8_t 數(shù)組，起始地址并未對齊到 DWORD，而是緊跟著 DLC？

您好，數(shù)組類型為uint_8，則按照該類型大小進(jìn)行內(nèi)存對齊，并不是將該數(shù)組作為整體計(jì)算大小進(jìn)行對齊。
您可使用__attribute__((aligned(4))) uint8_t Data[8];控制該成員變量的對齊形式，從而達(dá)到數(shù)組四字節(jié)對齊的效果。