General Description: When simulating RAMB* models the ADDRB must be valid for the DOB to be reset on the assertion of the SSRB.
Solution
The model incorrectly checks for the ADDRB to be valid ('1' or '0') before it will do the reset. This is a problem only in the PORTB of the RAMB models; the PORTA side is not dependant on the validity of ADDRA.
This problem will be fixed in a future update to the ISE software.