in the truth table of SR latch when S=R=1 o/p of latch is Q=~Q=0 which is invalid state.
While deriving the characteristic eqn for next state of SR latch, we use the k-map so when S=R=1 ; next state o/p is marked as X (Don't Care). we group four adjacent ones in k-map & two adjacent ones finally the o/p of SR Latch is Q(n+1) = S + Q(~R).
My question is since S=R=1 o/p of both NOR gate are 0 ( Q=0 & ~Q=0).
instead of marking zero in K- Map Q are Marked as X??? why so? as X (Dont Care) can be 0 or 1.
While deriving the characteristic eqn for next state of SR latch, we use the k-map so when S=R=1 ; next state o/p is marked as X (Don't Care). we group four adjacent ones in k-map & two adjacent ones finally the o/p of SR Latch is Q(n+1) = S + Q(~R).
My question is since S=R=1 o/p of both NOR gate are 0 ( Q=0 & ~Q=0).
instead of marking zero in K- Map Q are Marked as X??? why so? as X (Dont Care) can be 0 or 1.