Bootloader command set

AN3154

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DocID017063 Rev 5

3

Bootloader command set

The supported commands are listed in Table 2. Each command is further described in this

section.

Communication safety

Each packet is either accepted (ACK answer) or discarded (NACK answer):

•

ACK message = 0x79

•

NACK message = 0x1F

3.1

Get command

The Get command allows the host to get the version of the bootloader and the supported

commands. When the bootloader receives the get command, it transmits the bootloader

version and the supported command codes to the host.

Table 2. CAN bootloader commands

Command

Command code

Command description

1. Read protection – When the RDP (read protection) option is active, only this limited subset of commands is

available. All other commands are NACKed and have no effect on the device. Once the RDP has been

removed, the other commands become active.

0x00

Gets the version and the allowed commands

supported by the current version of the bootloader

Get Version &

Read Protection Status(1)

0x01

Gets the bootloader version and the Read Protection

status of the Flash memory

Get ID(1)

0x02

Gets the chip ID

Speed

0x03

The speed command allows the baud rate for CAN

run-time to be changed.

2. Please refer to STM32 product datasheet and AN2606 “STM32 microcontroller system memory boot

mode” to know which memory spaces are valid for these commands.

0x11

Reads up to 256 bytes of memory starting from an

address specified by the application

Go(2)

0x21

Jumps to user application code located in the internal

Flash memory or in SRAM

Write Memory(2)

0x31

Writes up to 256 bytes to the RAM or Flash memory

starting from an address specified by the application

Erase(2)

0x43

Erases from one to all the Flash memory sectors

Write Protect

0x63

Enables the write protection for some sectors

Write Unprotect

0x73

Disables the write protection for all Flash memory

sectors

Readout Protect(1)

0x82

Enables the read protection

Readout Unprotect(1)

0x92

Disables the read protection