Lab 7 - EE 421L 

Authored by: Kendrick De La Pena

Date: October 18, 2013

Email: delape19@unlv.nevada.edu

 

Lab Description

Lab 7 will focus on using buses and arrays to the design of word inverters, muxes, and high-speed adders

 

Lab Work

8-bit Inverter
Using buses, we can create an 8-bit inverter as shown below
00%20Bus%20Inv%20Schem.JPG
 
We can simulate the inverter to show the multiple inputs and outputs
00%20Bus%20Inv%20Circuit.JPG
00%20Bus%20Inv%20Graph.JPG
 
8-bit Gates
Similarly, buses can be used to create 8 bit gates. The following shown are: NAND, NOR, AND, and OR gates
02%208bit%20NAND.JPG 02%208bit%20NOR.JPG
02%208bit%20AND.JPG 02%208bit%20OR.JPG
 
The following is a simulation involving all gates in one schematic. B is equal to 10101011, and A is equal to 11111111 or 00000000
02%208bit%20Array%20Run.JPG
 
For the OR and NOR gate, A is equal to 11111111. As a result, the output for NOR is 00000000 while the output for OR is 11111111. For the AND and NAND gate, A is equal to 00000000. Thus, the output for NAND is 11111111 while the output for AND is 00000000
02%208bit%20Array%20Graph.JPG
 
2-to-1 Demux
A Demux acts as a selector for to different inputs. The schematic is shown below (the power and ground was added but not shown)
01%20Bus%20Demux%20Schem.JPG
 
The following shows how a demux works. If S equals 1, then A or 1 is chosen. If S equals 0, which means S inverse is 1, then B or 0 is chosen
01%20Bus%20Demux%20Run.JPG
01%20Bus%20Demux%20Graph.JPG
 Using buses, we can create an 8-bit demux. With an inverter, we no longer need an S inverse. Rather, we just use S and use the inverter to get the complement
01%20Bus%20Demux%208x%20Schem.JPG
  
Full Adder
Below is an alternative schematic for a full adder. Its function is the same
03%20Full%20Adder%20Schem.JPG
 
The following is a layout of the full adder
03%20Full%20Adder%20Layout.JPG
 
We can creat an 8-bit full adder with the use of buses
03%20Full%20Adder%208x%20Schem.JPG
 The following shows how the adder will work.
03%20Full%20Adder%208x%20Run.JPG
03%20Full%20Adder%208x%20IRSIMa.JPG
03%20Full%20Adder%208x%20IRSIMb.JPG
 

Return to Kendrick's labs