General Description: A case has been seen where MAP rejects a pack involving a LUT4 and MULTAND with shared signals. One of the shared signals is a GND net. The following error occurs:
ERROR:Pack:679 - Unable to obey design constraints (MACRONAME = Counter_block/PhyPktCntrCore/hset, RLOC = R6C0.S1) which require the combination of the following symbols into a single slice component: XORCY symbol "Counter_block/PhyPktCntrCore/BU100" (Output Signal = Counter_block/PhyPktCntrCore/N109) FLOP symbol "Counter_block/PhyPktCntrCore/BU101" (Output Signal = Counter_block/PhyPktCntr<19>) LUT symbol "Counter_block/PhyPktCntrCore/BU92" (Output Signal = Counter_block/PhyPktCntrCore/N713) MULTAND symbol "Counter_block/PhyPktCntrCore/BU93" (Output Signal = Counter_block/PhyPktCntrCore/N727) MUXCY symbol "Counter_block/PhyPktCntrCore/BU94" (Output Signal = Counter_block/PhyPktCntrCore/N729) XORCY symbol "Counter_block/PhyPktCntrCore/BU95" (Output Signal = Counter_block/PhyPktCntrCore/N108) FLOP symbol "Counter_block/PhyPktCntrCore/BU96" (Output Signal = Counter_block/PhyPktCntr<18>) LUT symbol "Counter_block/PhyPktCntrCore/BU97" (Output Signal = Counter_block/PhyPktCntrCore/N745) MULTAND symbol "Counter_block/PhyPktCntrCore/BU98" (Output Signal = Counter_block/PhyPktCntrCore/N759) MUXCY symbol "Counter_block/PhyPktCntrCore/BU99" (Output Signal = Counter_block/PhyPktCntrCore/N761) The function generator Counter_block/PhyPktCntrCore/BU92 is unable to be placed in the F position because there is a conflict for the F function generator input pins.
This error is due to a bug in constant pushing that makes the LUT connectivity incompatible with the MULTAND.
This is fixed in the first major release following version 3.1i, currently scheduled for July, 2001.