STM32F4 memory retained on programming

Question

Is there any memory on the STM32F407VG that is retained when a new program is flashed onto the chip?

I want to store a serial number on the device that is tied to the device, not the program.

I am aware there is a hardware identifier stored on the chip, but I want to create a more relevant number.

Answer 1

As Etienne said in his answer, you can use the backup registers or backup SRAM but those imply having a backup power source. What I have done for the STM32F3, is use the Flash as an Emulated EEPROM. The drivers are on the ST website, you reserve a few pages of Flash as your 'EEPROM' and write whatever information you want there. On startup your device can read those values or modify them during program execution.

Described here: AN3969.(Application Note from ST, you can just google the ref. #)

A safety measure wold be to change linker file so those flash pages don't accidentally get overwritten if your code should grow larger.

Answer 2

您可以使用备份寄存器（20*32bits），或备份SRAM（4kbytes）。

Answer 3

You can put this in the OTP area, which will keep the serial number for the life of the part.