Bootloader command set

AN3262

22/27

Doc ID 17845 Rev 2

The host sends the following bytes to the STM32W device:

Byte 1:

0x31

Byte 2:

0xCE

Wait for ACK

Bytes 3 to 6:

Start address (Byte 3 is the MSB and Byte 6 is the LSB)

Byte 7:

Checksum (XOR value of Bytes 3 to 6)

Wait for ACK

Byte 8:

Number of bytes to be received (0 < N

≤ 95)

N +1 data bytes (maximum of 96 bytes)

Byte 9:

Checksum (XOR value of N, N+1 data bytes)

Figure 24.

3.7

After sending the ACK byte, the bootloader receives one byte (the number of pages to be

erased), the Flash memory page codes and a checksum byte. If the checksum is correct,

the bootloader erases the memory and sends an ACK byte to the host; otherwise, it sends a

NACK byte to the host and the command is aborted.

●

The bootloader receives one byte containing N, the number of pages to be erased – 1.

(For 0

≤ N ≤115, N + 1 pages are erased.)

●

The bootloader receives (N + 1) bytes, each byte containing a page number.

Note:

No error is returned when performing erase operations on write-protected sectors.