Delta delay

InVHDLsimulations,allassignmentstosignals(a VHDL concept that represents anetconnecting different components together) occur with some infinitesimaldelay,known asdelta delay,unless a delay is specified.Technically, delta delay is of nomeasurableunit,but from adigital electronicshardware design perspective one should think of delta delay as being the smallesttime unitone could measure, such as afemtosecond(fs).