Keywords: XST, DSP, Xtreme, DSP48, slice
Urgency: Standard
General Description:
When a multiply function gets inferred into the XstremeDSP slice (DSP48), XST sets the LEGACY_MODE attribute to NONE. When the multiplier is used, the XtremeDSP operates 50 MHz slower than if no multiplier is used. This can lead to timing errors if the design is constrained to go faster than the XtremeDSP can handle.