Creative Education
2012. Vol.3, Special Issue, 856-858
Published Online October 2012 in SciRes (http://www.SciRP.org/journal/ce) http://dx.doi.org/10.4236/ce.2012.326128
856
Undergraduate Curriculum Development for Digital Integrated
Circuit Design
Xin Chen
Department of Electronic Science and Technology, Tongji University, Shanghai, China
Received August 29th, 2012; revised September 3 0th, 2012; accepted Octob e r 11th, 2012
This article describes the development of a Digital Integrated Circuit Design curriculum, which includes
how to select the design level and how to implement the design. The curriculum is for the undergraduates
in grade four, whose major is microelectronics. The development is in the background of very large scale
integrated circuits. Since the popular design flow is a hierarchy of abstraction levels, the goal of the cur-
riculum is to develop the students’ ability to design an actual circuit from scratch. Comparison is provided
from two aspects. The first aspect is the contents of various published textbooks. The second aspect is the
contents of similar courses in famous universities.
Keywords: Digital Integrated Circuit; Design Abstraction Level; Transistor Level; Gate Level; Hardware
Description Language
Introduction
Microelectronics is the base for modern information tech-
nology. And the digital integrated circuits are those who are
based on binary computation, which are the compositions for
microprocessors and communication circuits.
Currently, a digital integrated circuit may include thousands
of million transistors. For such a complicate design, design
method applies the abstraction level concept into the design
flow. According to specific design requirement, proper abstrac-
tion level (or levels) will be used to fulfill the design task. Ac-
cording to the increase order of the abstraction degree, the lev-
els are device, circuit, gate, functional module, and system, as
shown in Figure 1 (Rabaey et al., 2003). For undergraduates
whose major is microelectronics, and have finished merits in
device curriculum, circuit level is the next higher abstraction
level for them to explore. Gate level is the most popular thing
to study for microelectronic undergraduates in the past due to
the standard parts for gates or latches. Modular or systematic
design is studied in other curricula, such as Digital Logic, or
Computer Architecture, since it uses different strategies from
the formers’. With ASICs replaced standard parts, circuit level
design becomes very important in microelectronic industry.
Circuit level design is mostly proprietary to microelectronic
scope, since it needs knowledge of transistors, which will not in
detail be studied for majors other than micro electronics.
On the other hand, a digital integrated circuit can be imple-
mented on a chip sized in several square millimeters, which can
be a central processing system (Lai et al., 2008). For under-
graduate curriculum, they do not need to do such a complex
design that a module, such as adder or multiplier (Purohit et al.,
2009), will fit in their level. For implementation, there are mul-
tiple choices according to which kind of manufacturers you
choose. Nowadays, standard-cell and FPGA (Field Program-
mable Gate Array) based designs are popular due to their ability
to implement efficient design in performance or time-to-market
when compared to other approaches (Fey et al., 1989; Kriete et
al., 1984; Reis, et al., 1988; Nelson, 2008). Specifically, teach-
ers teach standard-cell designs to let students get to know the
manufacturers, and FPGA design to know its design tools ac-
cording to their nature .
This paper is in 4 sections. The 1st part is this introduction.
The 2nd part presents the contents of the curricula. The 3rd part
introduces the project phase of the curriculum. The 4th part is
conclusion.
Contents of the Curriculum
Contents of Textbooks Written by Famous Professors
in the World
With the copyright of those textbooks, some publishing
houses in time pressed textbooks for digital integrated circuits
design in both English and Chinese, such as “Digital Integrated
Circuits—A Design Perspective, 2nd Edition”, and its Chinese
version. Here we use this book in transistor level design, since
it introduces fundamental circuit cells from transistor equations,
which in a way similar to that of an analog integrated circuit
(Rabaey, 2003). Other book, such as “Digital Circuit Analysis
and Design with Simulink Modeling”, introduces digital inte-
grated circuits design from the view of digital logic and CPLD
(Complex Programmable Logic Device) or FPGA (Field Pro-
grammable Gate Array) (Karris, 2007). There are also books
for design flow, such as “Digital Integrated Circuit Design:
From VLSI Architectures to CMOS Fabrication” (Kaeslin,
2008).
Contents of Similar Courses in Other Universities
In University of British Columbia, course of Digital Systems
Design is based on the VHDL Hardware Description Language.
They will show how VHDL can be used to specify very large
systems at the modular or systematic level. And they have a
graduate level course for overview of deep submicron custom

X. CHEN
Figure 1.
Design hierarchy for digital circuit.
IC design, which is based on “physics of semiconductor de-
vices”, and presented in the transistor level (Alon, 2012). In UC
Berkeley, there is a course of Digital Integrated Circuits, which
is “an introduction to digital integrated circuits”. They will look
at various design styles and architectures as well as the issues
that designers must face. The material will cover CMOS de-
vices and manufacturing technology along with CMOS invert-
ers and gates. An advanced course of digital integrated circuits
focuses on the circuit design, optimization, and layout of very
high speed, high density or low power circuits for use in appli-
cations such as microprocessors, signal and multimedia proc-
essors, memory and periphery. “Special attention will devoted
to the most important challenges facing digital circuit designers
today and in the coming decade” (Lemieux & Mehrabadi, 2012).
How to Implement the Design
Since the goal of integrated circuit design is to implement a
microelectronic chip, it is needed to select a way. We select two
popular ways for students’ exercises, which can be found in
Figure 2 (Rabaey et al., 2003).
Analysis of Implementation Approaches
Firstly, concepts of “custom” and “semicustom” should be
taught. In fact, custom design is only used for small parts of the
processing unit with high performance. In other words, custom
design is suitable for a small-to-medium sized integrated circuit.
Commonly, semicustom design is used in large and very large
sized integrated circuit. In reality, a custom design process may
occur for a particular circuit block in the process of a semicus-
tom design.
In semicustom design, computer-aided-design tools are used
for the task. These tools can cover both the “cell-based” and the
“array-based” design. To do a cell-based design, cell libraries
are available in the tool suite. And standard cell or compiled
cell design is in the level of simple logic circuits. While the
macro cell design is usually in the level of modules. To do an
array-based design, things are different. “Pre-diffused” design
and “pre-wired” design are different from manners which they
finish the chip manufacturing processes. The former (“gate
arrays”) finishes the process in the manufacturer’s site after the
design, but the later finishes the process in the designer’s site.
With FPGA’s
With Xilinx design suite, the students may implement a sim-
ple system, such as a controller of traffic light. But this doesn’t
need the students design in the very transistor level, they just
describe the function of a module in HDL (Hardware Descrip-
tion Language), or call an existing one in supporting libraries.
In this way, they already have a chip (FPGA), and they com-
bine function units into what they want. But this way saves
both the time and the money to implement a design.
With Sta ndard Ce lls
With SPICE (the name of a circuit simulator) and corre-
sponding layout editor, such as Virtuoso and Dracula, the stu-
dents can implement a simple circuit such as an 8-bit adder or
an edge-triggered flip-flop, and based which, an 8-bit shift reg-
isters can be built. This is a real transistor level design. And the
result can be taped out for fabrication with a set of design rules
from a specific manufacturer. This way simulates the process in
which large volume products were needed.
Examples of the Results
In order to check the effects of the curriculum, students who
majored in other disciplines during their undergraduate years
are encouraged to attend the class. In result, they are able to do
projects with standard cells in their graduate period (Li, 2012).

X. CHEN
Figure 2.
Implementation methods.
Also, undergraduates of this major are encouraged to do pro-
jects for FPGA design, and finish more steps (such as the “code
coverage”) for the design when compared with their classmates
(Xiong, 2007).
Results
Digital Integrated Circuit Design is a very important part of
microelectronics. In the abstraction hierarchy of the design flow,
we focus on the circuit level to deliver our curriculum for un-
dergraduates in grade four with pre-requisites of device physics.
We choose FPGA and ASIC projects to deliver the post-course
exercises, which will implement the circuits in a real chip.
Students’ performance is excellent. Further focus should be
on the partition of curriculum hours between circuit level de-
sign and higher level design.
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