UART缺少字节

嗨，所有的人，都到了你盯着无数次，却看不到的地步。那就是我。我是一位经验丰富的设计师，多年来偶尔会有UART字节丢失的问题。这一次，我错过了，没有看到一个原因。我有一个PIC32 MX470接收数据包在UART，解析它们，然后回复UART。在很长一段时间，有时长达一个小时的周期性消息，一个字节在RX端丢失。下面是详细说明：FrReStuuUT中断是最高优先级字节被写入循环缓冲器，只有ISR写入此缓冲器（但丢失的字节不在缓冲器的边缘附近）。r）指向接收到的字节的位置的指针仅由ISR115200波特（每字节86个字节，如果我的数学正确）写的PIC时钟速率80 MHz（足够的时间来处理ISR并把接收到的字节填充到缓冲器中）“470 UART没有FIFO，但我不认为我是OV。错误的。（我应该检查一下，但我怀疑。）有没有想过我可能错过什么？谢谢你对我可能尝试的任何建议。戴夫



      以下为原文

    Hi All,

Ever get to the point where you've stared at something a zillion times but just don't see it?  That's me.  I am an experienced designer and have had problems with dropping UART bytes occasionally over the years.  This time I'm missing it and don't see a reason.

I have a PIC32MX470 which receives packets over UART, parses them, then replies over UART.  Over a long period of time, sometimes up to an hour of periodic messages, a byte gets lost on the RX side.

Here are details:

FreeRTOS
UART interrupt is highest priority
Bytes get written into a circular buffer and only the ISR writes this buffer (but the lost byte is nowhere near the edges of the buffer)
The pointer to the location where the received byte is saved is only written by the ISR
115200 BAUD (86 usec per byte, if my math is right)
PIC clock rate 80 MHz (plenty of time to handle the ISR and stuff the received byte into the buffer)

The '470 UART doesn't have a FIFO, but I don't think I'm overrunning.  (I should check this, but I doubt it.)

Any thoughts as to what I might be missing?

Thanks for any suggestions on what I might try.

Dave