Forum Discussion
New ContributorErasing a Volatile Key from Arria-10 GX
Yes, that was my original question and the goal.
Ad 1. I've recently received some info on this subject from one of the FAE's, that's very much under NDA, regarding the use of the internal JTAG in the discussed topic. I hope I won't violate the NDA by saying this: It's not impossible.
Ad 2. That's a very good point. Removing the VCCBAT indeed causes the POR and needs to be extended by external logic, i.e. a monoflip. Having an external security controller, it's easy to implement.
That solves my question. Thank You a lot!
Pawel
Super ContributorHi,
VCCBAT is a dedicated power supply for the volatile key storage. I believe the key will be gone if remove VCCBAT.
If you do not use the volatile key, refer to the respective device family pin connection guidelines for VCCBAT connection.
You can confirm if the volatile key is clear by perform the KEY_VERIFY JTAG instruction bit 20 to read out the information on the security features that are enabled on the chip. You can also verify by configure the FPGA without the key to ensure the volatile key is no longer needed. Refer figure on my next post.
Regards,
Aiman
- NurAiman_M_Intel
FvMI understand that original question is asking how volatile key can be cleared in user mode without using JTAG interface.
1. Unlikely by virtual JTAG operation. Virtual key register is part of dedicated JTAG hardware, not soft SLD infrastructure.
2. VCCBAT is monitored by POR comparator, removing it will most likely trigger power-on reset. Voltage level for key clearance is probably far below POR threshold. If you consider to switch off VCCBAT by logic output, consider to extend pulse duration by a monoflop.- PawelMa
Yes, that was my original question and the goal.
Ad 1. I've recently received some info on this subject from one of the FAE's, that's very much under NDA, regarding the use of the internal JTAG in the discussed topic. I hope I won't violate the NDA by saying this: It's not impossible.
Ad 2. That's a very good point. Removing the VCCBAT indeed causes the POR and needs to be extended by external logic, i.e. a monoflip. Having an external security controller, it's easy to implement.
That solves my question. Thank You a lot!
Pawel
