US 12,461,554 B2
System including a secure application configured to perform a clock update procedure
Ray Charles Marshall, Herts (GB); Mohit Satsangi, New Delhi (IN); and Andreas Bening, Henstedt-Ulzburg (DE)
Assigned to NXP USA, Inc., Austin, TX (US)
Filed by NXP USA, Inc., Austin, TX (US)
Filed on Aug. 30, 2023, as Appl. No. 18/458,748.
Claims priority of application No. 22208369 (EP), filed on Nov. 18, 2022.
Prior Publication US 2024/0168537 A1, May 23, 2024
Int. Cl. G06F 1/14 (2006.01); G06F 1/08 (2006.01); G06F 1/3237 (2019.01); G06F 21/57 (2013.01); G06F 21/72 (2013.01); G06F 21/74 (2013.01)
CPC G06F 1/14 (2013.01) [G06F 1/08 (2013.01); G06F 1/3237 (2013.01); G06F 21/57 (2013.01); G06F 21/725 (2013.01); G06F 21/74 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system comprising:
a real time clock, RTC, configured to keep a record of a current time,
at least one processor configured to execute at least a secure application and a non-secure application, wherein
the secure application is configured to operate in a first low-power-mode and a first normal-mode, wherein the secure application is configured to provide a secure clock for maintaining a secure record of the current time when operating in the first normal-mode, and wherein the secure clock is disabled during the first low-power-mode; and wherein
the non-secure application is configured to operate in a second low-power-mode and a second normal-mode, wherein the non-secure application is configured to perform a clock modification procedure to update the RTC via a second communication link between the non-secure application and the RTC when the non-secure application is operating in the second normal-mode and not when the non-secure application is operating in the second low-power-mode; and wherein
the system is configured to cause the secure application to perform a secure clock initialization procedure comprising obtaining the record of the current time from the RTC for initializing the secure clock based on a transition from the first low-power-mode to the first normal-mode, wherein
the secure application is configured to perform a clock update procedure as part of a transition from the first normal-mode to the first low-power-mode, the clock update procedure comprising, via a first communication link between the secure application and the RTC, providing for updating of the RTC with the secure record of the current time, and wherein
the system is further configured to prevent the non-secure application from performing the clock modification procedure after the clock update procedure has been performed, whilst the secure application is in the first low-power-mode and prior to the secure clock initialization procedure.