Apparatus and method for detecting a fault with a clock source

An apparatus comprising:

• a clock monitoring unit comprising:
• a first counter configured to receive a first clock signal from a first clock source and to count a first number of pulses in the first clock signal during a specified time period;
• and
• a controller configured to identify a fault with the first clock source when the first number does not have an acceptable value;
• and
• a fault injection unit configured to create an artificial clock fault in order to test whether the clock monitoring unit identifies the artificial clock fault.

A system comprising:

• a first clock source configured to generate a first clock signal;
• a clock monitoring unit comprising:
• a first counter configured to receive the first clock signal from the first clock source and to count a first number of pulses in the first clock signal during a specified time period;
• and
• a controller configured to identify a fault with the first clock source when the first number does not have an acceptable value;
• and
• a fault injection unit configured to create an artificial clock fault in order to test whether the clock monitoring unit identifies the artificial clock fault.