STM32F407VET6 LQFP-100在测试中发现设备授权码丢失的问题

[jinhui1-]

本批在测试一款STM32F407VET6，在测试中发现设备授权码丢失的问题。

1. 授权码的工作机制

设备生产通过软件发授权指令给到设备写入授权码，设备收到该指令后读取 FLASH ID ,然后进行加密，把加密后的数据写入 OTP 区(0x1FFF7800) , 编程成功后读出来验证是否写入成功，如果成功则重新启动，否则返回失败。

2、问题分析

通过单步调试，FLASH ID 是正确的，但是读出来 OTP 的数据有一部分变为

全零了，所以数据比对不通过。

[KDJEM.1]

Hello @jinhui1- and welcome to the community :),

Thanks to develop your posts in English so it helps us, and the users of our community understand your question and try to help you.

STM32F407VET6 LQFP-100 found that the device authorization code was lost during testing

This batch is testing an STM32F407VET6, and during the test it was discovered that the device authorization code was lost.

1. How the authorization code works

Equipment production sends authorization instructions through software to the device to write the authorization code. After receiving the instruction, the device reads the FLASH ID, then encrypts it, and writes the encrypted data into the OTP area (0x1FFF7800). After the programming is successful, read it out to verify whether The write is successful, if successful, restart, otherwise return failure.

2. Problem analysis

Through single-step debugging, the FLASH ID is correct, but part of the OTP data read becomes All are zero, so the data comparison fails.

What is the Rev_Id of STM32F407VET6 devices you are using?

Could you please share a photo of device top marking?

Thank you.

Kaouthar