How to Implement Flash Memory Diagnostic (FLASH_SM_0) without Using X-CUBE-STL on STM32G4

[saurabhkore]

Hello,

I am working with an STM32G431 MCU and referring to the STM32G4 Series Safety Manual (UM2454). In section 3.6.4 (Embedded Flash Memory) — Table 21: FLASH_SM_0, it describes a periodic software test for Flash memory using signature-based methods (e.g., CRC).

According to the document, this diagnostic can be implemented via X-CUBE-STL, but I would like to implement it manually, without using the STL library.

My goal is to verify Flash memory integrity periodically or at startup by computing a CRC over a defined Flash region and comparing it with a stored “golden” reference signature in Flash.

I would like to understand the following:

1. What is the correct approach to implement FLASH_SM_0 manually according to the safety manual’s requirements?

2. How should I select the Flash regions for testing (code, data, unused memory)?

3. What is the recommended way to store and update the reference (golden) CRC signature in Flash?

4. Are there any STM32 hardware CRC peripheral examples or best practices for this type of diagnostic?

5. Should this test be executed at startup only, or periodically during runtime as well?

Any guidance, example code, or references from similar safety implementations would be very helpful.

Thankyou.