Patent ID: 8854049
Filing Date: 2014-10-07
Classification: G01R

Abstract:
1. A timer unit for measuring a period of time of an operation of a logic circuit comprising: a timer for measuring the period of time said logic circuit has been in a non-normal mode different from a normal operation mode; a comparator connected to said timer, for comparing said measured period of time with a maximum for the period of time said logic circuit is allowed to be in said non-normal mode and outputting an error signal signifying a fault in operation of the logic circuit in the non-normal mode when said measured period of time exceeds said maximum; and a mode detector for detecting a switching of said logic circuit from a normal operation mode to said non-normal mode, said mode detector being connected to said timer, for automatically starting said timer upon a detection of a switching of said logic circuit to said non-normal mode and automatically stopping said timer upon a detection of a switching of said logic circuit out of said non-normal mode.