Tool/software:
Hi,
My customer has read the AM263x Safety Manual, and have some questions about DCC (Dual Clock Comparator).
Could you help to answer to their questions below ?
[ Purpose ]
They are using 25MHz System Clock Input. They want to detect the failure by using DCC when the clock input is fixed in Hi, fixed in Lo or drifted.
[What to Check]
1. Is their recognition below correct as an overview of DCC functions?
- Can select the reference clock and the clock to test.
- There is a counter for each reference clock and the clock to be tested, and the counter is decremented.
Set the expected ratio for both counts to zero, and output an error if the ratio deviates from the expected ratio.
2. They’re recognizing that it is possible to detect system clock drift failure by setting each clock to the following. Are they correct ?
- Reference clock (REF) : On-chip RC transmitter (e.g. RCCLK10M)
- Clock tested (TEST) : System Clock (External Crystal Oscillator 25 MHz)
3. The on-chip RC transmitter is independent of the system clock. It starts working when the CPU is powered on. Is this correct ?
Thanks and regards,
Hideaki
