DocID017063 Rev 5

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AN3154

Bootloader command set

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The STM32 sends messages as follows:

ACK message: Std ID = 0x73, DLC = 1, data[0] = ACK if the content of the command is

correct and ROP is not active else data[0] = NACK.

3.11

Readout Protect command

The Readout Protect command is used to enable the Flash memory read protection. When

the bootloader receives the Readout Protect command, it transmits the ACK message to the

host if ROP is disabled else it transmits NACK. After the transmission of the ACK message,

the bootloader enables the read protection for the Flash memory.

At the end of the Readout Protect command, the bootloader transmits the ACK message

and generates a system Reset to take into account the new configuration of the option byte.

Figure 24. Readout Protect command: host side

1. RDP_PRM = Readout Protect.

The host sends the messages as follows

Command message: Std ID = 0x82, DLC = 0x01, data[0] = 00.