Daniel D - Department für Informatik - Universität Oldenburg

10. Februar 2006
Laudatio anlässlich der
Verleihung der
Ehrendoktorwürde
Dr. - Ing. h.c. an
Herrn Prof. Dr. Daniel D.
Gajski
Prof. Dr. Franz Rammig

Magnifizen z , dear Dan, dear Anna, Ladies an d
Gentlemen,
Today we are honouring a hero of Com puter
Science. I could characterize him as one of the
grand old men in Electronic Design
Auto mation. But I will not. First of all Prof.
Daniel Gajski is not an old m a n at all and on
the other hand people m ay think that by grand
I want to characterize his tall appearance. So I
prefer to call him a hero.
At m a ny u niversities oral exa minations as part
of a PhD - exa m start with the head of the
exa mination com mittee introducing the
candidate via his CV. Today we do not have an
exa m: Who of us could examine Prof. Gajski!
Nevertheless I will s hortly recall his CV:
Daniel D. Gajski did receive his Diploma in
Engineering an d his Master of Science degree in
Electrical Engineering fro m the University of
Zagreb, Croatia. In 1974 he did receive his
Ph.D. in Com p uter Science fro m the University
of Pennsylvania at Philadelphia.
Now he was ready for m ajor impacts on
com p uter industry. For 10 years he was a
practitioner in the areas of digital circuit
design, su per computing and VLSI design. The
results were convincing but for a genius like
Prof. Gajski the pers pectives in industry do not

each far enough. So he decided to join
acade mia again. And of course not just
acade mia but one of the m ost prestigious
u niversities in computer science: the University
of Illinois at Urbana - Cha m paign. Finally he
contributed substantially to the high
reputation of the Infor mation an d Com puter
Science Depart ment of the University of
California at Irvine. Here he holds the Henry
Sa m ueli Endowed Chair in the Depart ments of
Electrical and Com puter Engineering an d
Com puter Science and is foun der an d director
of UCI’s Center of Embedded Com puter
Syste ms.
Due to his pioneering contributions to VLSI
design, to Syste m Level Design an d for his
work on CAD tools he was appointed IEEE
Fellow.
So, let’s speak about the scientific contributions of
Prof. G ajski:
I re me m ber very well w hen in the early nineties he
used a party at m y ho me in Paderborn to test the
reaction of a E uropean audience to his ironical dinner
speech given so me days later at E U R O D A C in
H a m b urg. T his speech w as entitled “Publish or
Perish: T he E asy W a y”. N o other person could have
given such an ironical speech better than D a niel
G ajski. H e always tried the hard w ay!

The scientific fields where Prof. Gajski m a de
s ubstantial contributions are m a nifold an d his
achievements are highly impressive.
At Urbana - Cha m pain, he concentrated his
research on parallel processing and computer
architecture. He was the principal architect of
the CEDAR m achine, the leading US
s u perco m p uter project at that time. There
were only few re markable scientific papers in
the field of s u perco m p uter architectures at
this time that did not reference the research
carried out by Prof. Gajski.
In the sequel Daniel Gajski concentrated his
research on the design process of digital
syste ms. His achievements cover m a ny as pects
of this area. He es pecially contributed to
for malize and auto mate the design process,
fro m s pecification down to implementation.
These efforts have later been extended by him
towards embedded syste ms. His develop ment
of m o deling techniques, design languages, and
algorith m s to su p port s pecification, analysis,
validation and synthesis of e mbedded
com p uter syste m s has substantial impact on
the entire field.
Daniel Gajski is an outstanding visionary. This
enabled him to discover funda mental
principles in the design of digital syste m s.
Once he com plained that the m ost cited of his
n u merous p ublications is this one with the
least content. He m eant his fa mous article

where he introduced what is known as Gajski’s
Y-diagra m today. With that assess ment of his
article, however, he was u nnecessarily
u n pretentious. Before Gajski’s Y-diagra m has
been introduced there was a great confusion
an d fruitless discussions about str ucturing the
design process an d the docu ments produced
d uring this process. Just by or dering the
docu ments in two orthogonal aspects, na mely
levels of abstraction an d views he succeeded to
sort out the chaos. He identified the
fun da mental views of behaviour, structure and
geometry an d initiated a discussion about the
levels of abstraction to be considered when
designing digital syste ms. This contribution
was a great achievement in an acade mic sense.
From now on it was m uch easier to teach
st u dents how to design digital syste m s; it
beca me m uch easier to identify research areas
u n d uncovered research challenges. Even m ore
important: this result allowed the design
auto mation industry to develop so
s uccessfully. As there was a general agree ment
now, which type of docu ments have to be
pro duced d uring the design process and how
these docu ments can be categorized it also
beca me m uch clearer what type of tools are
necessary to create these docu ments. As a
result the design of digital syste ms is
categorized and har monized in a way m uch
s u perior to m ost other engineering disciplines.
When people use digital electronics as the
exa m ple of rapidly developing technology: the

principle driving force is design auto mation.
And design auto mation needs well un derstood
principles and categories. So it was just this
little article by Dan Gajski which did light the
fire!
Daniel Gajski’s did not just light the fire, he
also fuelled it s ubstantially. During the last
three decades he achieved pioneering results.
He was a principal contributor to the areas
Silicon Compilation, High - Level Synthesis, an d
Syste m - Level Design.
In the eighties Daniel Gajski m a de m ajor
contributions in the develop ment of Silicon
Com pilation. This was the first time when
digital circuits have been developed based on a
for mal s pecification. In those days this
approach was com pletely novel. It beca me the
starting point of electronic design auto mation
as used everywhere in industry today.
In the late eighties Daniel Gajski became one of
the m ain pioneers in creating the research area
of
High - Level Synthesis. Following his strict
scientific way of thinking he introd uced very
clear definitions of proble ms to be solved,
developed new algorith m s and implemented
s uccessful prototypes. He was well ahead of
the general develop ment. Concepts of High
Level Synthesis are entering industrial
application just now; m ore than a decade after
Dan Gajski’s pioneering work. The “Interactive
Synthesis Environ ment (ISE)” m ay serve as an

exa m ple. It was developed un der the
leadership of Dan Gajski, introduced
s uccessfully to the m arket an d finally resulted
in foun ding YExplorations, Inc., a start - u p
com pany that develops advanced High - Level
Synthesis tools and brings the m to m arket.
In the early nineties Daniel Gajski m oved his
concern to the completely new area of
Syste m - Level design. He created new
approaches for an integrated develop ment of
HW-
/SW - Systems. Together with his research
group he developed the so called „100 - hour
design cycle“, which resulted in a tre mendous
enhance ment of productivity an d design time
reduction. For this p urpose Dan Gajski
developed the first generation of syste m level
design languages an d tools: SpecCharts and
SpecSyn. They successfully addressed the new
challenges of syste m level design.
Prof. Gajski never rests content with achieved
results. So in the late nineties he developed a
second generation of Syste m - Level Design
methods u n d tools, now based on the C -
language. At the sa me time these techniques
allow reuse of design components (IPs or
COTs) in a well structured m a n ner.
Daniel Gajski is Spiritus Rector an d leader of a
research tea m that developed the language
SpecC an d the design method based on this
language. This language definition ha d a
worldwide impact on both, acade mia and

industry. In 1999 a couple of leading
com panies created the SpecC Technology Open
Consortiu m (STOC) in or der to further an d
stan dar dize the SpecC technology. Today STOC
is for med by m ore than 30 u niversities and
m ore than 30 companies, including INTEL,
Motorola, NEC, Sony, Toshiba, an d Yamaha.
Concepts and results of Dan Gajski can be
found also in other leading Syste m Level
design languages an d design flows, as widely
accepted in industry. The SpecC language as
well as its metho dology is cited as reference
an d inspiration for the develop ment of
Syste mC, which currently is m ostly used in
Syste m Level design. In addition a couple of
newly founded com panies (e.g. InterDesign
Technologies, Inc. in Japan) rest on SpecC
technology.
Daniel Gajski is foun der and director of the
Center for Embedded Com p uter Syste ms
(CECS) at the University of California at Irvine.
CECS is a leading research institute for
embed de d applications in the auto motive,
com m u nications and me dical areas. Currently
CECS consists of 22 faculty me m bers and 70
graduate students in the fields of Com puter
Science, Electrical Engineering, Aerospace, an d
Medical Science. We at Heinz Nixdorf Institute
in Paderborn are prou d that a for mal
cooperation agreement of our two institutes
s hows the signature of Prof. Gajski.

In his acade mic career Dan Gajski was advisor
of m ore than 30 Ph.D. st u dents. In the m ean -
time they became either professors at
prestigious universities or went to leading
com panies of the EDA industry like Synopsys,
Cadence, Mentor Graphics. In m ost cases these
for mer st u dents of Dan Gajski became key
persons in their companies.
There is no serious person of the acade mic or
industrial com m u nity in the EDA field that
does not know Prof. Gajski. As a consequence
the invited talks, key note ad dresses, an d
tutorials given at prestigious conferences or
for leading com panies cannot be counted. In
addition he has been invited to innu merable
panel discussions an d guest lectures.
It is not sur prising that he was chairing the
progra m com mittees of m ore or less each
serious conference in the field and was
reviewer for all m ajor conferences, journals,
an d book series. His advice has been asked for
by the govern ment an d by compa nies.
Daniel Gajski is editor, author and co - author
of seven books and nu merous book chapters.
So he is co - editor of the book " Advanced
Com puter Architectures” (IEEE Press, 1986)
an d editor of the book " Silicon Com pilation
"(Reading, MA: Addison - Wesley, 1988). He co -
authored the books „High Level Synthesis: An
Introduction to Chip and Syste m Design” (New
York: Kluwer - Acade mic,1992), “Specification

an d Design of Embedded Systems” (Englewood
Cliffs, NJ:
Prentice Hall, 1994), “SpecC: Specification
Language an d Methodology” (Boston:
Kluwer - Acade mic, 2000), an d “Syste m - level
Design: A Practical Guide with SpecC”
(Boston: Kluwer - Acade mic, 2001). Finally he is
author of the textbook "Principles of
digital Design“" (Englewood Cliffs, NJ: Prentice
Hall, 1995) used worldwide at u niversities for
teaching digital design. Dan Gajski’s books
have been translated into m a ny languages an d
are highly acknowledged as leading books of
the res pective areas. In addition to his books
Dan Gajski p ublished m ore than 200 papers in
leading jour nals and conferences. He received
a couple of best pa per awar ds and
no minations. He is holding five patents in the
area of computer design. A couple of
stan dar disation com mittees have been chaired
by him or he was me m ber of the m.
It is not sur prising that Dan Gajski received
n u merous research grants d uring his
professional career.
To su m u p: Prof. Daniel Gajski m a de
fun da mental contributions to the state of the
art in the field electronic design auto mation. A
great impact on the way how digital HW/SW -
syste ms are designed today in theory and
practice can be observed.

The Carl von Ossietzki Universität Oldenburg
is just the right place to honour Prof. Daniel
Gajski by a p hilosop hical doctor for honour’s
sake. There are long lasting research
connections, especially to the grou p of Prof.
Nebel. Dan Gajski gave a couple of talks here in
the infor matics colloquiu m and gave
s ubstantial advice to a couple of Ph.D. stu dents
in Oldenburg. Teaching in technical
infor matics at the University of Oldenburg is
heavily influenced by the results of Dan
Gajski’s research.
Prof. Daniel Gajski and honourable
representatives of the Carl von Ossiet zki
Universität Oldenburg: I would like to
congratulate both; Prof. Daniel D. Gajski for his
p hilosophical doctor degree for honour’s sake
an d the University for being honoured at the
sa me time by s uch an outstan ding scientist
a mong its laureates.
Thank you very m uch!