AN3262 datasheet(22/27 Pages) STMICROELECTRONICS

22 / 27 page

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.

WRITE MEMORY packet example

3.7

ERASE MEMORY command

The ERASE MEMORY command enables the host to erase Flash memory pages. When the

bootloader receives the ERASE MEMORY command, it transmits the ACK byte to the host.

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.

ERASE MEMORY command specifications:

●

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.

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