Description
No. The enhanced PLL does not have a dynamic enable or disable control port for just the automatic clock switchover circuitry; you cannot manually control whether automatic switchover was on or off. You must program the PLL with automatic switchover either enabled or disabled.
You can enable the clock sense circuitry but not enable the automatic switchover feature. By enabling the clock sense circuitry, two PLL output ports, CLKBAD0
and CLKBAD1
, are enabled. These ports indicate whether the primary or secondary clocks have stopped running. Then, using custom-designed logic, you can manually toggle the CLKSWITCH
control port to decide whether the PLL switches from primary to secondary or back.