Struct Frame 

pub struct Frame {
    pub cmd: Cmd,
    pub status: Status,
    pub addr: u32,
    pub len: u16,
    pub data: Data,
    pub crc: [u8; 2],
    /* private fields */
}

Wire frame: SYNC(2) + CMD(1) + STATUS(1) + ADDR(4) + LEN(2) + DATA(len) + CRC(2)

Used for both requests and responses. For requests, status is Status::Request. For responses, cmd and addr echo the request.

Single instance, reused each iteration of the protocol loop.

Fields

cmd: Cmd

Command code.

status: Status

Response status (always Status::Request for requests).

addr: u32

Flash address (for Write/Erase) or mode selector (for Reset).

len: u16

Data payload length in bytes (0..64).

data: Data

Payload data (union-typed).

crc: [u8; 2]

CRC16 over the frame body (little-endian).

Implementations

impl Frame

pub fn send<W: Write>(&mut self, w: &mut W) -> Result<(), W::Error>

Send the frame. Two write_all calls: body, then CRC.

pub fn read<R: Read>(&mut self, r: &mut R) -> Result<Status, ReadError>

Read one frame from the transport.

Syncs on preamble, reads header + payload, validates CRC. Returns Ok(Status::Ok) on success, Ok(Status::*) for protocol errors (CRC, invalid frame, overflow), Err only for transport IO.

pub async fn send_async<W: Write>(&mut self, w: &mut W) -> Result<(), W::Error>

Async version of send.

pub async fn read_async<R: Read>( &mut self, r: &mut R, ) -> Result<Status, ReadError>

Async version of read.

Trait Implementations

impl Default for Frame

fn default() -> Self

Create a default frame. Data buffer is uninitialized — read() or caller writes populate it before use.