Built-in alarms are available to monitor internal events. Two types of alarms and upsets are detected by this feature:
- SYSREF caused internal clocks to be realigned
- An upset that affects the internal clocks
When an alarm occurs, a bit for each specific alarm is set in ALM_STATUS. Each alarm bit remains set until the host system writes a 1 to clear it. If the alarm type is not masked (see the
ALM_MASK register), then the alarm is also indicated by the ALARM register. The CALSTAT output pin can be configured as an alarm output that goes high when an alarm occurs. See CAL_STATUS_SEL in the
CAL_PIN_CFG register.