The DCC uses two independent clock sources to detect when one is out of specification. Each DCC module implements the following features:
- Two independent counter blocks count clock pulses from each clock source
- Each counter block is programmable, however, for proper operation the counters must be programmed with seed values that respect the ratio of the two clock frequencies
- Configurable timebase for error signal
generation
- Error signal generation when one of the clocks is out of specification
- Clock frequency measurement
- Ability to continue the check in continuous
mode despite the error. This is programmable
capability.
- Ability to register up-to 4 readings of the
error for all associated counts in FIFO.
- Synchronized handoffs between counting clock
domains, processing clock domain or reporting
clock domains (bus clock).