MPS PMBUS PASSWORD PROTECTION
Do processor circuit ICs (VRM) really have passwords?
Do you remember the video where I explained how to program modern processor circuit ICs using a PMBUS programmer? I mentioned at the time that in some cases, we would need the schematic, because even though there are many dump files available now, for some models it’s not possible to backup the file from another board because the ic is protected.
This is because some modern processor VRM ICs support a feature called
PMBUS Protect. This feature allows the manufacturer to set a password to protect the IC. It provides three levels of protection:
- Protection from reading the registers
- Protection from writing to the registers
- Protection from both reading and writing to the registers
For the first and third types, it's not possible to take a backup from the IC—even if you have a working board with the same model. In this case, you’ll need the schematic to manually build a configuration that suits the processor circuit and its components.
As for the second type, you can still take a backup and write it to a new or used VRM IC later without any issues.
Are there any ways to break this protection? No.
Are there any workarounds to bypass it? No.