AR# 564: FPGA COMPILER: PULLUPs/PULLDOWNs must be instantiated when using Synopsys.
FPGA COMPILER: PULLUPs/PULLDOWNs must be instantiated when using Synopsys.
Can PULLUPs and PULLDOWNs be inferred or do they have to be instantiated ?
PULLUP and PULLDOWN components may be inferred on pad connections of input and output cells. These I/O cells have attributes that allow you to infer PULLUP or PULLDOWN resistors using the set_pad_type command in Synopsys tools. For example, to attach a PULLUP resistor to an input port named INPUT1, type:
set_pad_type -pullup INPUT1
Internal PULLUPs must be INSTANTIATED, they cannot be inferred.