I have been working for a long time with ADSP-2187N in 144-BGA package (ADSP-2187NBCA-320) giving it as input clock a 40MHz sine wave (3Vpp) without any problem. Datasheet doesn't specify other characteristics.
For obsolescence of BGA, I have switched to a 100-Lead LQFP (ADSP-2187NBSTZ-320).
Now I'm finding some strange behaviours like not correct assignment of ASTAT register and strange freezes of the processor. I've tried with a 40MHz square wave (3.3Vpp) at the CLKIN input and now it seems working fine.
Is this the real problem even though datasheet doesn't say anything, or do I miss something else?
Thank you for your help.