用心讀資料

When URXSE, URXIEx and GIE are set and a start edge occurs on URXDx,
the internal signal URXS will be set. When URXS is set, a receive interrupt
request is generated but URXIFGx is not set. User software in the receive
interrupt service routine can test URXIFGx to determine the source of the
interrupt. When URXIFGx = 0 a start edge was detected and when URXIFGx
= 1 a valid character (or break) was received.

 

設置了URXSE導致UART接收到的總是最後一位，查資料看了半天，雖然用眼睛看卻沒有用心看，師兄指導一下，從上面一段英文資料裏面看得很清楚，爲什麼當時看到這段文字等於什麼都沒有看到呢？

所有的東西都是別人的，吸收之後纔是自己的

加油