4.2 UART Command/Response Transport Layer

The MDFU UART Transport Layer is responsible for reliably transporting commands and responses across a UART byte stream interface.

Transmitting a command across a UART byte stream interface results in several challenges when receiving a command. There’s a similar set of challenges when the host is receiving responses.

• How does the client know where the first byte of the command is in the byte stream?
• How does the client know where the last byte of a command is in the byte stream?
• How does the client detect if the command was corrupted during transmission?

The following sections of the MDFU UART Transport Layer describe a UART command-response framing mechanism which allows the detection of the start and end of a command/response and also allows for the detection of corruption of commands and responses.