LPC4353 USART3 receive variable number of chars

[skysky]

lpc4353 usart3 used as UART slave,and receive master's frame data-Binary.but Master send the number of data is variable,and also any time and any number.LPC4353 need receive a whole frame,the parse the frame.

So,whethe has a good way to receive the whole frame data?

[kerryzhou · Accepted solution]

Hi Sky sky,

     Actually, this is a communication question.

    The universal method is defined a user serial communication protocol, it normally contains: Header byte, lengh byte, data frame.

  Take an example: 0xA5 0X5A 0X02 0X01 0X02

 0xA5 0X5A  is the head byte

  0X02  is the data length need to receive

  0X01 0X02 is the detail data.

  So, as a UART slave, your LPC4353 can receive the data all the time, when it receives 0XA5 0X5A, it means the new frame is beginning,  the next byte is the data byte length, after receive the data length byte, the following just need to receive the according length data, other data will be discarded.

    The above thought is the normal usage, just for your reference.

Wish it helps you!

If you still have question, please contact me!

Have a great day,
Kerry

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[skysky]

thanks your answer.

my intention is that first receive the whole frame into ringbuff.then parse the received frame.

So i need know when the frame has been received completely.

Now i used the USART's BI(Break Interrupt).And the uart Master set the usart BREAK after the frame has been sent