I am wondering if it is safe to apply a voltage or clock to the CLKIN pin when device is upowered (VDD = 0 V)?
I see that the Absolute Maximum Ratings section says the voltage can be -0.5 to 3.6 V, regardless of VDD, so I am assuming this is OK, but I just want to be sure.
Also, is there any clamping that I need to be aware of, or will the CLKIN pin be high impedance when VDD = 0V?