Data EEPROM 0x55/0xAA write unlock codes

Figured I'd ask this question as my microcontroller experience is relatively new and I've only been exposed to PIC microcontrollers. Out of curiosity, are those unlock codes used by any other uC's on the market as data EEPROM write protect unlock codes besides the PIC? Or are they exclusive to the PIC?

It seems to be pretty well the norm on Mircochip EEprom and equivalents. However! It doesn't seem to be used on microwire (microchip also does these)

Atmel used it with their EEproms. I don't know about anyone else.