We have a project that using a wiegand sensor to power the mcu and update the counter to FRAM through SPI. there will be a 10us width regulated power supply from wiegand, all the process need to be done in 10us with below sequence:
- power on STM32 and FRAM
- read value of counter from FRAM
- increase/decrease counter
- store new value to FRAM
If you have the selection suggestion of STM32 or other arm factory, please let me know, thanks.