1a. (4 points) Your best friend, Luke, has created a startup company called Walking in the Sky. Luke could
use a help in getting the company up and running. Luke has a vision that he has to create the following
combinational circuit.
A
B
NAND2
C
NV
NOR2
XUH2
Out
Luke has contacted a vendor called The beRels and the table below shows the propagation delay for
each logic gate:
Gate Propagation delay in ns (nano seconds)
2-input NAND 10
Inverter 5
2-input NOR 9
2-input XOR 11
Find the total signal propagation delay:
a. From signal A to Out
b. From signal B to Out
c. From signal C to Out
d. From signal D to Out
1b. (3 points) A critical path is the longest path that a signal can take. Out of your answer for 1a, 1b, 1c,
and 1d, which one has the longest/biggest propagation delay?
1c. (3 points) The shortest path is the shortest path that a signal can take. Out of your answer for 1a, 1b,
1c, and 1d, which one has the smallest propagation delay?
