12.4.7 Clock Monitor

The clock monitor's purpose is to detect system clock failure or anomalies and allow the system to take action. The clock monitor uses a second clock (reference) source to compare to the clock being monitored. Clock monitors are assigned to a clock source such as a CLKGEN, PLL output or other system clocks including FRC. The clock monitor provides the following features:

  • Configurable Clock Sources:
    • Monitored clock sources
    • Reference clock sources
  • Flexible Detection Capability
  • Clock Frequency Drift Detection
  • Selectable Threshold Limits for Warning and/or Failing
  • Monitored Clock Catastrophic Detection
  • Reference Clock Catastrophic Detection
  • User Optimizable Accuracy via:
    • Accumulation time adjustment
    • Selectable clock sources
  • Register Write Protection
  • Fault Injection Capability
  • Frequency Measurement
  • Pulse Width and Duty Cycle Measurement
Figure 12-13. Clock Monitor Architecture