10.1.36.4 Subtractor Implementation Rules

The following table lists the implementation rules for a subtractor.

Table 10-147. Implementation Rules
ParameterFamilyValueDescription
LPMTYPEAllLPM_ADD_SUBSubtractor category
LPM_HINTProASICPLUS, ProASICSKSUBSklansky model
FBKSUBFast Brent-Kung model
BKSUBCompact Brent-Kung model
ALLFSUBAVery fast carry select model
ALLRIPSUBARipple carry model
LPMTYPEAxceleratorLPM_FC_ADD_SUBFast carry chain Subtractor category
LPM_HINTFC_FSUBFast carry chain select model
LPM_HINTFC_RIPSUBFast carry chain ripple carry model
Note: FSUB and MFSUB are not recommended for ProASIC3/E or ProASICPLUS devices.