Month: September 2018

 
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Build a Hardware Accelerator

 

 

Amir Darvishi, Wael Badawy “Build a Hardware Accelerator“Circuit Cellar August 2005, pp.24 – 29

 

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Review of Principles of verifiable RTL design

By Lionel Bening and Harry Foster, Kluwer Academic Publishers, 2000.

Using verifiable RTL design, an engineer can add or improve the use of cycle-based simulation, two-state simulation, formal equivalence checking, and model checking in the traditional verification flow. Furthermore, a verifiable RTL coding methodology permits the engineer to achieve greater verification coverage in minimal time, enhances cooperation and support for multiple EDA tools within the flow, clarifies RTL design intent, and facilitates emerging verification processes.

This book addresses verification of synchronous designs. It provides a comprehensive understanding of various verification processes from conceptual and practical approaches. The concepts presented in this book are drawn from author experience with large-scale system design projects. It draws a technique methodology for verifiable RTL coding. The book is divided into nine chapters as follows. Chapter 1 provides a short introduction of this book. Chapter 2 introduces four principles of RTL design (fundamental verification principle, retain useful information principle, orthogonal verification principle, and functional observation principle) and issues related to verifiable RTL (design specification, test strategies, coverage analysis, event monitoring, and assertion checking). Chapter 3 introduces the basics of the RTL methodology and addresses the problem of complexity due to competing tool coding requirements. It introduces a simplified and tool-efficient Verilog RTL verifiable subset using an object-oriented hardware design (OOHD) methodology. Moreover, it details a linting methodology, which is used to enforce project-specific coding rules and tool performance checks. Chapter 4 presents the history of logic simulation, followed by a discussion on applying RTL simulation at various stages within the design phase. Chapter 5 discusses RTL and the formal verification process. It presents the concept of finite state machine FSM and its analysis and applicability to proving machine equivalence and FSM properties. Chapter 6 discusses ideas on verifiable RTL style. Chapter 7 provides examples on the common mistakes that are involved with projects, designers, and EDA verification tool developers. Chapter 8 presents a tutorial on Verilog language elements that can be used to build a verifiable RTL model. Chapter 9 summarizes the 21 fundamental principles of verifiable RTL Design, which are discussed throughout the book.

This book is considered one of the milestones for verifiable RTL design. It shows an efficient methodology for writing a verifiable RTL, and it defines guidelines for large-scale systems. I believe that every engineer working in the area of RTL design should read this book.

 

 

Wael Badawy, “Principles of verifiable RTL design“, IEEE Circuits and Devices Magazine, Vol. 18, Issue 1, January 2002, pp. 26 -27

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A Co-design Methodology for High-Performance Real-time Systems

Wael M. Badawy, Ashok Kumar and Magdy A. Bayoumi “A Co-design Methodology for High-Performance Real-time Systems” The Canadian Journal on Electrical and Computer Engineering, Vol. 26, July/October 2001, pp. 141-146.

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MPEG-4 for Multimedia Streaming

 

Wael Badawy, “MPEG-4 for Multimedia Streaming” Circuit Cellar, December 2001, pp. 36-40.

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System On Chip: Trends and Challenges

The increase in the number of transistors that can be integrated on a single chip allows the integration of more functions. On the other hand, time-to-market pressures require novel techniques for developing integrated circuits. System on chip is a methodology that allows the integration of several third-party cores with an embedded processor. This paper presents a tutorial for the system- on-chip methodology and presents the design tasks that are involved in developing a system on chip.

L’accroissement du nombre de transistors qu’il est possible d’inte ́grer sur une puce permet d’offrir plus de fonctionnalite ́s. D’autre part, les pressions de la mise en marche ́ rapide de celles-ci exige l’e ́laboration de techniques nouvelles de de ́veloppement de circuits inte ́gre ́s. Les syste`mes sur une puce repre ́sentent une me ́thodologie de de ́veloppement qui permet l’inte ́gration de com- posantes provenant de plusieurs de ́veloppeurs et de les combiner a` un processeur embarque ́. Cet article pre ́sente un tutoriel sur la me ́thodologie de conception de circuits sur une puce et pre ́sente les taˆches de design implique ́es dans le de ́veloppement de tels systemes.

Wael Badawy, “System On Chip: Trends and Challenges,” The Canadian Journal on Electrical and Computer Engineering, Vol. 26, July/October 2001, pp. 85-90.

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Algorithm-Based Low Power VLSI Architecture For 2d-Mesh Video Object Motion Tracking

The new VLSI architecture for video object (VO) motion tracking uses a novel hierarchical adaptive structured mesh topology. The structured mesh offers a significant reduction in the number of bits that describe the mesh topology. The motion of the mesh nodes represents the deformation of the VO. Motion compensation is performed using a multiplication-free algorithm for affine transformation, significantly reducing the decoder architecture complexity. Pipelining the affine unit contributes a considerable power saving. The VO motion-tracking architecture is based on a new algorithm. It consists of two main parts: a video object motion-estimation unit (VOME) and a video object motion-compensation unit (VOMC). The VOME processes two consequent frames to generate a hierarchical adaptive structured mesh and the motion vectors of the mesh nodes. It implements parallel block matching motion-estimation units to optimize the latency. The VOMC processes a reference frame, mesh nodes and motion vectors to predict a video frame. It implements parallel threads in which each thread implements a pipelined chain of scalable affine units. This motion-compensation algorithm allows the use of one simple warping unit to map a hierarchical structure. The affine unit warps the texture of a patch at any level of hierarchical mesh independently. The processor uses a memory serialization unit, which interfaces the memory to the parallel units. The architecture has been prototyped using top-down low-power design methodology. Performance analysis shows that this processor can be used in online object-based video applications such as MPEG-4 and VRML

Wael Badawy and Magdy Bayoumi, “Algorithm-Based Low Power VLSI Architecture For 2d-Mesh Video Object Motion Tracking,” The IEEE Transaction on Circuits and Systems for Video Technology, Vol. 12, No. 4, April 2002, pp. 227-237

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MRI Data Compression Using a 3-D Discrete Wavelet transform

A low-power system that can be used to compress MRI data and for other medical applications is described. The system uses a low power 3-D DWT processor based on a centralized control unit architecture. The simulation results show the efficiency of the wavelet processor. The prototype processor consumes 0.5 W with total delay of 91.65 ns. The processor operates at a maximum frequency of 272 MHz. The prototype processor uses 16-bit adder, 16-bit Booth multiplier, and 1 kB cache with a maximum of 64-bit data bandwidth. Lower power has been achieved by using low-power building blocks and the minimal number of computational units with high throughput.

Published in:

Engineering in Medicine and Biology Magazine, IEEE  (Volume:21 ,  Issue: 4 )

Wael Badawy, Guoqing Zhang, Mike Talley, Michael Weeks and Magdy Bayoumi, “MRI Data Compression Using a 3-D Discrete Wavelet transform,” The IEEE Engineering in Medical and Biology Magazine, Vol. 21, Issue 4, July/August 2002, pp. 95-103.

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A VLSI Architecture for Video Object Motion Estimation using a Novel 2-D Hierarchical Mesh

 

This paper proposes a novel hierarchical mesh-based video object model and a motion estimation architecture that generates a content-based video object representation. The 2-D mesh-based video object is represented using two layers: an alpha plane and a texture. The alpha plane consists of two layers: (1) a mesh layer and (2) a binary layer that defines the object boundary. The texture defines the object’s colors. A new hierarchical adaptive structured mesh represents the mesh layer. The proposed mesh is a coarse-to-fine hierarchical 2-D mesh that is formed by recursive triangulation of the initial coarse mesh geometry. The proposed technique reduces the mesh code size and captures the mesh dynamics.

The proposed motion estimation architecture generates a progressive mesh code and the motion vectors of the mesh nodes. The performance analysis for the proposed video object representation and the proposed motion estimation architecture shows that they are suitable for very low bit rate online mobile applications and the motion estimation architecture can be used as a building block for MPEG-4 codec.

Wael Badawy “A VLSI Architecture for Video Object Motion Estimation using a Novel 2-D Hierarchical Mesh,” Journal of Systems Architecture, ISSN 1383 – 7621, invited

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A Novel Current-Mode Instrumentation Amplifier Based on Operational Floating Current Conveyor,

 

This paper presents a novel current-mode instrumentation amplifier (CMIA) that utilizes an operational floating current conveyor (OFCC) as a basic building block. The OFCC, as a current-mode device, shows flexible properties with respect to other current- or voltage-mode circuits. The advantages of the proposed CMIA are threefold. First, it offers a higher differential gain and a bandwidth that is independent of gain, unlike a traditional voltage-mode instrumentation amplifier. Second, it maintains a high common-mode rejection ratio (CMRR) without requiring matched resistors, and finally, the proposed CMIA circuit offers a significant improvement in accuracy compared to other current-mode instrumentation amplifiers based on the current conveyor. The proposed CMIA has been analyzed, simulated, and experimentally tested. The experimental results verify that the proposed CMIA outperforms existing CMIAs in terms of the number of basic building blocks used, differential gain, and CMRR.

Published in:

Instrumentation and Measurement, IEEE Transactions on  (Volume:54 ,  Issue: 5 )

Yehya H. Ghallab, and Wael Badawy, Karan V.I.S. Kaler and Brent J. Maundy, “A Novel Current-Mode Instrumentation Amplifier Based on Operational Floating Current Conveyor,” IEEE Transaction on Instrumentation and Measurement, Volume 4, October 2005, pp. 1941 – 1949.

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Obiter.

By George Neilson.

 

THE claims of the legal profession to culture were cleverly belittled by Burns, when he made the New Brig of Ayr wax sarcastic over the town councillors of the burgh:—

“Men wha grew wise priggin owre hops an’ raisins,

Or gathered lib’ral views in Bonds and Seisins.”

Bonds and seisins are certainly not the happiest intellectual feeding ground. “I assure you,” said John Riddell, a great peerage antiquary, “that to spend one’s time in seeking for a name or a date in a bit of crabbed old writing does not improve the reasoning powers.” Riddell was a keen critic of Cosmo Innes, who subsequently had the happiness of passing the comment upon Riddell’s observation that “perhaps it is not in reasoning that Mr. Riddell excels.” Yet the annals of the law shew many splendid examples of the union of close textual study of manuscript, with an enlarged outlook on first principles and with keen critical insight. Perhaps Madox was a more permanently serviceable scholar than Selden. One can see from Coke’s margins, his infinite superiority to Bacon in exact knowledge at first hand of older English law. But when all is said, we could have done much better without Coke and Madox than without Bacon or Selden. It is delightful to be able to appeal to Chaucer for perhaps the most emphatic compliment to law, in respect to its capacity for literature, that it has ever received. Amongst all the Canterbury pilgrims, there was no weightier personage than the Man of Law:—

“Nowher so bisy a man as he ther nas,

And yet he semed bisier than he was.

In termes hadde he caas and domes alle

That from the tyme of King William were falle,

Therto he coude endyte and make a thing

Ther could no wight pinche at his wryting,

And every statut coude he pleyn by rote.”

Yet it was this learned and successful counsel, alone of the party, who knew the poet’s works through and through, and had the list of them at his finger-ends. Good Master Chaucer for this touch we offer hearty thanks! Was it in Herrick’s mind when he penned his fine tribute to Selden?

“I, who have favoured many, come to be

Graced, now at last, or glorified by thee.”

 

Wits and poets have had many hard things to say in jest and in earnest about the legal profession and its work. Herrick bracketed law and lawyers with diseases and doctors, in a fashion hinting that the relation of cause and effect existed between both pairs:—

“As many laws and lawyers do express,

Nought but a kingdom’s ill-affectedness.

Even so those streets and houses do but show

Store of diseases where physicians flow.”

 

It was an old story this linking of the practitioners of law and medicine in one yoke of abuse. The reason given for both categories in early satire is sufficiently curious. It was because they took fees! Walter Map declared the Cistercian creed to be that no man could serve God without mammon. Ancient satire equally objected to the service of man, either legally or medically, under these conditions. “The Romaunt of the Rose” has the traditional refrain of other strictures in verse, when it declares that

“Physiciens and advocates,

Gon right by the same yates,yates, gates

They selle hir science for winning.winning, gain

  • ···

For they nil in no maner greeno kind of good will

Do right nought for charitee.”

 

The same idea, precisely, finds voice in the poem attributed to Walter Map, wherein the doctor and the lawyer come together under the lash, because no hope can be based upon either of them unless there be money in the case. “But if the marvellous man see coin, the very worst disease is quite curable, the very falsest cause just, praiseworthy, pious, true, and pleasing to God.” Perhaps these ancient sarcasms were keener on the leech than the lawyer. “The Romaunt of the Rose” goes so far as to say that if the physicians had their way of it,

“Everiche man shulde be seke,

And though they dye, they set not a leke

After: whan they the gold have take

Ful litel care for hem they make.

They wolde that fourty were seke at onis!

Ye, two hundred in flesh and bonis!

And yit two thousand as I gesse

For to encresen her richesse.”

 

No doubt the men of medicine would have been much more vulnerable on another line, for it was no satirist but a learned medical professor, Arnauld de Villeneuve, who, in the beginning of the fourteenth century, advised his students as follows:—“The seventh precaution,” said he, “is of a general application. Suppose that you cannot understand the case of your patient, say to him with assurance that he hath an obstruction of the liver.” No legal professor surely was ever guilty of the indiscretion of saying such a thing as this!

 

The ineradicable public prejudice against legal charges as flagrantly exorbitant is only a modified form of an older idea exemplified above that lawyers should have no fees at all. And as to this day the plain man has never fully reconciled himself to the doctrine that the lawyer is only an agent, and not called upon to sit in the first instance in judgment on his client, so in the past the professional defence of a criminal appeared a very venal transaction.

“Thow I have a man i-slawe,

And forfetyd the kynges lawe

I sal fyndyn a man of lawe

Wyl takyn myn peny and let me goo.”

 

How reprehensible a thing to take fees was long reckoned admits of curious illustration. “Before the end of the thirteenth century,” says that never-failing authority, Pollock and Maitland’s “History of English Law,” “there already exists a legal profession, a class of men who make money by representing litigants before the courts and by giving legal advice. The evolution of this class has been slow, for it has been withstood by certain ancient principles.” Amongst these retarding influences lay the half-religious scruple about the propriety of payment—men as usual swallowing the camel first and straining at the gnat afterwards. Of course the subject had to be illuminated by monkish tales and death-bed repentances. There was, according to the Carlisle friar who penned the “The Chronicle of Lanercost,”—writing under the year 1288,—a young clerk in the diocese of Glasgow, whose mind “was given rather to the court of the rich than to the cure of souls. He was called Adam Urri, and was laically learned in the laic laws, disregarding the commands of God against the Praecorialia [so in the printed text, but, query, Praetorialia?] of Ulpian. He used the statutes of the Emperor in litigating causes, for payment of money. But when he had grown old and famous in this his wickedness, and was striving by his astuteness to entangle the affairs of a poor little widow, the divine mercy laid hold on him, assailing his body with sudden infirmity, and bringing his mind to plead (enarraret) more for another life.” Condemning utterly the lawyer’s court, he turned over a new leaf, predicted the day of his own death, and died punctually conform to the prophecy, leaving an example unctuously used by the friar to teach future generations “how wide was the gulf betwixt the service of God and the vanity of this world.” We shall not be far wrong in regarding, as of more historic interest, the indication of the immorality of fees, and the important reference to Ulpian as an authority in the forum causidicorum of thirteenth century Scotland.

 

Amongst the amiable conceptions of the middle age was the notion that the Evil One often manifested a particular zeal against sin. He was regarded with a different eye from that with which we regard him, and he rewarded faith with actual appearances such as only spiritualists can now-a-days command. Some of them were not very engaging, however praiseworthy may have been their object and occasion. Simeon of Durham, an eminently respectable contemporary author, wrote of the death of King William Rufus in the year 1100 that the popular voice considered the wandering flight of Tyrell’s arrow a token of the “virtue and vengeance of God.” And he added that about that time the Devil had frequently shewn himself in the woods “and no wonder, because in those days law and justice were all but silent.” The logic of this because, not apparent on the surface, becomes less obscure when it is remembered that in the mediæval devil the character of Arch-Enemy is so much subordinated to that of Arch-Avenger.

 

The direct relation of not only the Saints but of the Deity itself to human affairs was a conception so clear to the mediæval mind that it saw nothing irreverent in a title deed being taken in the Supreme name, or in marshalling “Deus Omnipotens” at the head of the list of witnesses to a charter. This anthropomorphic practice gave occasion to one of the sharpest of Walter Map’s jokes against the Cistercians. Three abbots of that order petitioning on behalf of one of their number and his abbey for the restoration of certain lands by King Henry II. as having been injuriously taken away from the claimant’s abbey, represented to the King in his court that for God’s sake he ought to cause the lands to be restored and they assured him and gave him God himself as their guarantor (fidejussorem) that if he did, God would greatly increase his honour upon earth. King Henry found it difficult to resist the appeal thus made to him but called the Archdeacon Walter Map to advise. This he did well-knowing that this counsellor did not love the Cistercians, and that he might thus find a creditable way out of a tight corner. The Archdeacon was equal to the occasion. “My lord,” said he to the King, “they offer you a guarantor; you should hear their guarantor speak for himself.” “By the eyes of God,” replied Henry, “it is just and conform to reason that guarantors themselves should be heard upon the matter of their guarantee.” Then rising with a gentle smile (not a grin, expressly says Giraldus Cambrensis) the shrewd monarch retired leaving the disappointed abbots covered with confusion.

 

Of the many ties between literature and law, one, not by any means the least interesting on the list, is the quantity of legal citations, phrases, metaphors and analogies which got swept into the wide nets of the poets. Amongst such scraps there are few so successful and still fewer so pathetic as one in which a metrical historian, drawing near the close, both of his days and his chronicle, figured himself as summoned on short induciæ at the instance of Old Age to appear at a court to answer serious charges, where no help was for him save through grace and the Virgin as his advocate.

Elde me maistreis wyth hir brevis,elde, age

Ilke day me sare aggrevis,brevis, writ

Scho has me maid monitiouneilke, each

To se for a conclusiounequhilk, which

The quhilk behovis to be of det;of det, of right

Quhat term of tyme of that be set

I can wyt it be na way,wyt, know

Bot weill I wate on schort delay

At a court I mon appeire

Fell accusationis thare til here

Quhare na help thare is bot grace.bot, without

The maikless Madyn mon purchacemaikless, matchless

That help; and to sauff my statepurchace, procure

I haiff maid hir my advocate.sauff, save

Androw of Wyntoun’s verse it must be owned was verse on the plane of a notary public, and oft the common form of legal writ supplied sorrily enough the deficiencies of his imagination. But here for once the simple dignity of the thought bore him up and carried him through.