Unexplained issue with an ST Microelectronics STM32F100C6T6 MCU

[Sheen 78]

Hello All,

I have been working on a rather sophisticated switch-mode power supply out of a Crown professional audio amplifier.

The STMicroelectronics STM32F100C6T6 is used on the power supply PCB for housekeeping. It is also responsible for turning on/off of the unit.

[DavidAlfa]

Upload the binary file, might give some hints.
Before programming, are you checking if the config RDP and WRP protection bits are all off?
If PB8 blinks, and it's not the power supply itself, clearly the MCU isn't being erased.

Must be the psu somehow. Have you checked the output with a scope? Maybe a slow turn-on or noisy output is triggering it.

[wek]

It doesn't appear to regain "Virgin" status after a global erase

What exactly do you mean by "global erase"?

JW

PS. There are two bytes for user data storage in the Option Bytes, see Data0 and Data1 in PM0063.
PS2. If state is stored in FLASH - or in abovemention Option Bytes - the FLASH cells in question can be "worn out" if endurance limit is exceeded. FLASH cells then may excessively leak charge, not being able to retain their state. The result is unreliability in time and at elevated temperature, not necessarily detectable by simple checks when erasing/programming.