-Design Criteria-
Design a combinational logic circuit that has three inputs and seven outputs. As the inputs (X, Y, and Z) count from 000 to 111, the seven outputs (a) through (g) will generate the logic required to display your date of birth on a seven-segment display.
-Design constraints-
- The seven-segment display must be a common cathode.
- Current limiting resistors (150 W - 270W) must be used.
- The Karnaugh mapping technique must be used to obtain the simplified logic expression for each of the seven segments.
- At least one segment must be implemented with NAND only logic.
- At least one segment must be implemented with NOR only logic.
- The implementation of the remaining segments is left to your discretion.
-procedure-
-errors-
After prototyping the circuit, Segment D was working "wonky." Since the circuit was simulated against the truth table, and worked properly, it meant the problem was a human error in the breadboarding. I began troubleshooting Segment D. I knew the chip had power, as the 74LS02 also powered Segment G, which was working properly. I cross referenced my IC pinouts with the breadboard and it appeared to be wired correctly. Upon further inspection I noticed that I was actually one pin off. I should have been using pins 11-13, but was actually connected to pins 12-14. This caused the output of the LS7402 to always see 5v and caused segment D to never turn off. After a quick switch of the wires, everything worked properly.