General Description: I am using a multiplier core from CORE Generator, and the multiplier type is set as "Non-Constant Parallel Multiplier." When I run MAP with the "-u" option, the following error message is reported:
"ERROR:Pack:679 - Unable to obey design constraints (MACRONAME = multiplier_v2_0_lat_v2/top_level/par_mul/m2/top, RLOC = X2Y9), which require the combination of the following symbols into a single slice component: LUT symbol "BU104" (Output Signal = N46687) MULTAND symbol "BU105" (Output Signal = N46689) MUXCY symbol "BU106" (Output Signal = N45586) MULTAND symbol "BU109" (Output Signal = N46745) The output signal of the MULT_AND symbol BU109 must be connected to the input of a MUXCY symbol within the slice. Please correct the design constraints accordingly."
解决方案
1
The work-around is to NOT use the "-u" switch when running MAP.
For GUI users: Be sure to have the "Trim unconnected signals" option selected in the GUI or Properties menu. (The default setting is already selected.)
For command line users: Do NOT use "-u" when running the MAP command.
This problem was fixed in a multiplier core that was released in (E_IP1) in October, 2001.
2
If the "-u" switch is necessary, set the following environment variable: