Patent ID: 11880454
Assignee: QUALCOMM INCORPORATED
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 14:
15. A voltage-frequency security monitor (VFSM) to prevent a malicious attack on subsystem hardware, the VFSM comprising:
a component configured to monitor a clock frequency (Fclk) from a first source to the subsystem hardware and a supply voltage (Vdd) from a second source to the subsystem hardware to prevent the malicious attack on the subsystem hardware;
a dynamic variation monitor (DVM) comprising tunable delay elements;
an auto-calibration circuit configured to perform auto-calibration of the tunable delay elements of the DVM and generate an auto-calibration code value in response to each voltage change notification signal or each frequency change notification signal indicating change of the clock frequency (Fclk) or the supply voltage (Vdd) of the subsystem hardware; and
a controller configured to compare the auto-calibration code value with a threshold reference calibration value to determine whether the malicious attack is occurring, and configured to change at least one of the clock frequency (Fclk) or the supply voltage (Vdd) in the subsystem hardware to a predefined value when the malicious attack is detected.