US 11,880,454 B2
On-die voltage-frequency security monitor
Bharat Kumar Rangarajan, Bangalore (IN); Dipti Ranjan Pal, Irvine, CA (US); Keith Alan Bowman, Morrisville, NC (US); Srinivas Turaga, Bangalore (IN); Ateesh Deepankar De, Bangalore (IN); Shih-Hsin Jason Hu, San Diego, CA (US); and Chandan Agarwalla, San Diego, CA (US)
Assigned to QUALCOMM Incorporated, San Diego, CA (US)
Filed by QUALCOMM Incorporated, San Diego, CA (US)
Filed on May 14, 2020, as Appl. No. 16/874,538.
Prior Publication US 2021/0357502 A1, Nov. 18, 2021
Int. Cl. G06F 21/55 (2013.01); G06F 1/26 (2006.01)
CPC G06F 21/554 (2013.01) [G06F 1/26 (2013.01); G06F 2221/034 (2013.01)] 20 Claims
OG exemplary drawing
1. A method comprising:
monitoring a clock frequency (Fclk) from a first source to subsystem hardware and a supply voltage (Vdd) from a second source to the subsystem hardware to prevent a malicious attack on the subsystem hardware;
performing on die auto-calibrating of tunable delay elements of a dynamic variation monitor (DVM) configured to use 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;
comparing the auto-calibration code value with a threshold reference calibration value to determine whether the malicious attack is detected; and
changing 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.