Introduction to VLSI Programming Lecture 5: Tangram

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Introduction to VLSI Programming Lecture 5
Tangram Tools

• (course 2IN30)
• Prof. dr. ir.Kees van Berkel

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Time table 2005
date class lab subject
Aug. 30 2 0 hours intro VLSI
Sep. 6 3 0 hours handshake circuits
Sep. 13 3 0 hours handshake circuits assignment
Sep. 20 3 0 hours Tangram
Sep. 27 no lecture
Oct. 4 no lecture
Oct. 11 1 2 hours demo, fifos, registers deadline assignment
Oct. 18 1 2 hours design cases
Oct. 25 1 2 hours DLX introduction
Nov. 1 1 2 hours low-cost DLX
Nov. 8 1 2 hours high-speed DLX
Nov. 29 deadline final report
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Lecture 5

• Outline
• Recapitulation Lecture 4
• Tangram overview
• Compilation Tangram ?Handshake Circuits
• Tools
• Demonstration
• Lab work assignment fifos and registers

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Handshake signaling and data
push channel versus pull channel
request ar
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Tangram assignment x f(y,z)
Handshake circuit
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Two-place wagging buffer
byte type 0..255 wag2 main
proc(a?chan byte b!chan byte).begin x,y
var byte a?x forever do (a?y
b!x) (a?x b!y) odend
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Four 8?8 shift registers compared
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Tangram/Haste

• Purpose programming language for asynchronous
  VLSI circuits.
• Creator Tangram team _at_ Philips Research Labs
  (proto-Tangram 1986 release 2 in 1998).
• Inspiration Hoares CSP, Dijkstras GCL.
• Lectures no formal introduction manual hand-out
  (learn by example, learn by doing).
• Main tools compiler, analyzer, simulator, viewer.

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2-place buffer

• byte type 0..255
• BUF1 proc (a?chan byte b!chan byte).begin
  x var byte forever do a?x b!x od end
• BUF2 main proc (a?chan byte c!chan
  byte).begin b chan byte BUF1(a,b)
  BUF1(b,c) end

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Median filter

• median main proc (a? chan W b! chan W).
  begin x,y,z var W xy, yz, zw var bool
  forever do ((zy yx) yzxy)
  a?x (xy xlty zx zltx) if zxxy
  then b!x or xyyz then b!y or yzzx
  then b!z fi odend

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Greatest Common Divisor

• gcd main proc (ab?chan ltltbyte,bytegtgt c!chan
  byte).begin x,y var byte forever do
  ab?ltltx,ygtgt do xlty then y y-x or xgty
  then x x-y od c!x odend

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Nacking Arbiter

• nack main proc (a?chan bool b!chan
  bool).begin na,nb var bool ltltna,nbgtgt
  ltlttrue,truegtgt forever do sel probe(a) then
  a!nb na nanb or probe(b) then b!na
  nb nbna les od end

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C Tangram ? handshake circuit
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C Tangram ? handshake circuit
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C Tangram ? handshake circuit
C (RS)
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Tangram Compilation Theorem
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VLSI programming of asynchronous circuits
behavior, area, time, energy, test coverage
Tangram program
feedback
compiler
simulator
Handshake circuit
expander
Asynchronous circuit
(netlist of gates)
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Tangram tool box

• Let Rlin4.tg be a Tangram program
• htcomp -B Rlin4
• compiles Rlin4.tg into Rlin4.hcl, a handshake
  circuit
• htmap Rlin4
• produces Rlin4.v files, a CMOS standard-cell
  circuit
• htsim Rlin4 a b
• executes Rlin4.hcl with files a, b for
  input/output
• htview Rlin4
• provides interactive viewing of simulation results

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Tangram program Conway
P
Q
R
a
b
c
d

• B1 type 0..1 B2 type ltltB1,B1gtgt
  B3 type ltltB1,B1,B1gtgt P Q
  R conway main proc (a?chan B2
  d!chan B3). begin b,c chan B1 P(a,b)
  Q(b,c) R(c,d) end

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Tangram program Conway

• P proc(a?chan B2 b!chan B1). begin x var
  B2 forever do a?x b!x.0 b!x.1 od end
• Q proc(b?chan B1 c!chan B1). begin y var
  B1 forever do b?y c!y od end
• R proc(c?chan B1 d!chan B3). begin x,y,z
  var B1 forever do c?x c?y c?z d!ltltx,y,zgtgt
  od end

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Lab work assignments 1 and 2

• Assignment 1 shift registers
• Assignment 2 fifos
• See separate handout.

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Lab-work and report

• You are allowed to team up with a colleague (Not
  mandatory.)
• Report more than listing of functional Tangram
  programs
• analyze the specifications and requirements
• present design options, alternatives, trade-offs
• motivate your design choices
• explain functional correctness of your Tangram
  programs
• analyze explain area, time, energy of your
  programs.

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Course grading

• Your course grading is based on
• the quality of your Tangram programs 30
• your final report on the design and evaluation
  of these programs (guidelines will follow)
  30
• a concluding discussion with you on the programs,
  the report and the lecture notes 20
• your results on an intermediate assignment.
  20

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Next time lecture 6 (2005, Oct 17)

• Outline
• Tangram arithmetic resource sharing
• Lab work assignments on arithmetic resource
  sharing