Lab

Lab 7 - EE421L

Authored by Rhyan Granados

Email: granar1@unlv.nevada.edu

10/23/20

Goal

Using buses and arrays in the design of word inverters, muxes, and high-speed adders

Prelab

I backed up my work for Lab 6

I completed Tutorial 5 as seen below

Schematic:

Sim:

Sim with init. condition of osc_out at 0V:

Alternative More Concise Schematic:

Final Layout:

Schematic for Layout:

LVS:

Symbol:

Sim Schematid:

Sim Results:

The Lab

1) Simulate the 4-bit inverter circuit

Show, in your lab report, how a capacitive load influences the delay and rise/fall times.

As you can see from the graph, since out<1> has the largest load attached to it, it will have the longest rise time. While, out<0>takes the least amount of time to rise due to having no load.

2) Create schematics and symbols for an 8-bit input/output array of: NAND, NOR, AND, inverter, and OR gates.
Provide a few simulation examples using these gates.

	Schematic	Symbol	8-Bit Schematic
NAND
NOR
AND
inverter
OR

Simulation of all 2-input gates:

3) Next examine the following schematic of a 2-to-1 DEMUX/MUX (and the symbol). Simulate the operation of this circuit using Spectre and explain how it works.

1-Bit Mux/Demux

Schematic

Symbol

1-Bit 2:1 Demux/Mux

Schematic

Symbol

1-Bit 2:1 Mux Sim

As we can see on the simulation, the multiplexer works by using S to choose the output signal Z. So if S is high then it will pass A's signal as the output Z, and if S is low(Si becomes high due to the inversion) and B's signal is passed through as the output Z.

1-Bit 2:1 Demux Sim

As we can see from the sims the demultiplexer does the opposite of the multiplexer. Instead of using S to choose which signal to pass through as the output Z, it takes Z as the input and uses S to decide where Z will go. So if S is high then Z goes to A and inversely goes to B when it's low.

4) Create an 8-bit wide word 2-to-1 DEMUX/MUX schematic and symbol.Include an inverter in your design so the cell only needs one select input, S (the complement, Si, is generated using an inverter).Use simulations to verify the operation of your design.

Note: So I already included the inverter in part 3) so I will just re-use it

8-Bit 2:1 Mux Sim