6.3.4 NAND with edge evaluation
The output of a NAND with edge evaluation is only 1 at least one input is 0 and all inputs were 1 during the
last cycle.
The output is set to 1 for the duration of one cycle and must be reset to 0 at least for the duration of the next
cycle before it can be set to 1 again.
A block input that is not used (x) is assigned: x = 1.
Timing diagram of a NAND with edge evaluation