Computer Assignment #1
Digital VLSI Systems
©Mohammad Sharifkhani, Fall 2011.
Getting familiar with Linux environment, technology and IC design tools
Characterization of MOS transistors
Transistor level modeling of basic gates
characterization of a basic inverter gate in the target technology
acterization of the
Simulate a unit size PMOS and NMOS with W=1um/L=0.2um in CMOS technology. What
are the key character
istics of the devices?
Observe the velocity saturation, report your observation using some figures.
How much is the equivalent resistance
using the simulations
Is it consistent
with the characteristics of the device derived in a? why
equivalent RC and c
heck the accuracy of your modeling)
What is the conductance ratio in this technology?
Part 2: Design and characterization of a CMOS inverter
Using the information you obtained in Part 1, design a fully symmetric CMOS
Characterize VM, internal capacitance and fan
out 4 delay of the inverter with typical
rise time and fall times? (Hint: use a chain of inverter to create typical rise/fall times.)
Find the technology parameters for the capacitance of a minimum w
idth wire in the
technology with a unit length of 1um between metal layers of M1
Draw the layouts of the wires and perform the DRC. Extract the layout and observe that
the information provided in the tech. documents is con
sistent with the extracted netlist.
How much is the energy c
onsumption of the inverter for a transition?
(verify your result
What is the equivalent capacitance of a 200um M1 wire in a minimum distance
separated bus in terms of the
capacitance of a unit size CMOS inverter?
Use a ring oscillator and verify the result you obtained in c.