General Description: CORE Generator Multiplier v3_0 does not function properly when CE is low. (This applies to Pipelined and Parallel Multipliers.)
The multiplier does function properly when CE is constantly high. However, when CE is brought low to disable the multiplier, the multiplier will continue to output incorrect data. This problem will not be seen in the behavioral simulation; however, it can be seen during post-NGDBuild simulation and during the device operation.
To work around this problem, generate a multiplier with a handshaking signal ND pin enabled. The ND pin should be tied to Vcc constantly, and the CE pin should function properly.
This problem has been fixed in Multiplier v4_0, which is available in 4.1i IP Update #1.