How to protect non-volatile data from mass erase?

[M F]

Posted on July 04, 2017 at 10:50

Hello everyone,

we need to protect certain calibration data we store in a STM32L051 microcontroller from being deleted by mass erase operations.

The scenario is as follows:

1- Our production stores some calibration bytes together with a firmware in the microcontroller non-volatile memory. The calibration information is device specific. This calibration values should not be deleted, as indicated, in the entire life of the device.

2- Our customer receives this microcontroller together with an API from us. He/she then creates his own application with the help of the API. Once created, he/she downloads his/her application in the STM32L051 microcontroller, replacing the default firmware from our production.

The question again, how to prevent that the calibration data is not lost if a mass erase is performed?

Thanks in advance for your ideas!

MF

[M F]

Posted on July 05, 2017 at 09:48

Thanks for your input, Andrei.

Yes, OTP memory is what I'd like to have in my STM32L051 controller to solve this issue easily and in a clean manner.

In the controller's datasheet I have not found that OTP is available.

The OTP is available, however, in devices like the STM32F4xx indicated in RM0090 manual.

Due to price reasons changing microcontroller or adding external memory is, for the time being, out of question.