1. Introduction to VLSI Programming Lecture 5: Tangram & Tools
(course 2IN30)
Prof. dr. ir.Kees van Berkel

2. Time table 2005 date class | lab subject Aug. 30 2 | 0 hours
intro; VLSI
Sep. 6
3 | 0 hours
handshake circuits
Sep. 13
handshake circuits assignment
Sep. 20
Tangram
Sep. 27
no lecture
Oct. 4
Oct. 11
1 | 2 hours
demo, fifos, registers | deadline assignment
Oct. 18
design cases;
Oct. 25
DLX introduction
Nov. 1
low-cost DLX
Nov. 8
high-speed DLX
Nov. 29
deadline final report
7/29/2019
Kees van Berkel

3. Lecture 5 Outline: Recapitulation Lecture 4 Tangram overview
Compilation: Tangram Handshake Circuits
Tools
Demonstration
Lab work: assignment “fifos and registers”
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Kees van Berkel

4. Handshake signaling and data
request ar
active side
passive side
acknowledge ak
data ad
push channel
versus
pull channel
request ar
active side
passive side
acknowledge ak
data ad
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Kees van Berkel

5. Tangram assignment x:= f(y,z)yw zw y f z  
xw0 | x xr
xw1 y f z   y f z   | x | x
Handshake circuit
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Kees van Berkel

6. 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) od end
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7. Four 88 shift registers compared
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8. Tangram/Haste
Purpose: programming language for asynchronous VLSI circuits.
Creator: Tangram Philips Research Labs (proto-Tangram 1986; release 2 in 1998).
Inspiration: Hoare’s CSP, Dijkstra’s GCL.
Lectures: no formal introduction; manual hand-out (learn by example, learn by doing).
Main tools: compiler, analyzer, simulator, viewer.
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Kees van Berkel

9. 2-place buffer BUF1 a b c 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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Kees van Berkel

10. Median filter
median: main proc (a? chan W & b! chan W). begin x,y,z: var W & xy, yz, zw: var bool | forever do ((z:=y; y:=x) || yz:=xy) ; a?x ; (xy:= x<=y || zx:= z<=x) ; if zx=xy then b!x or xy=yz then b!y or yz=zx then b!z fi od end
Median a b
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Kees van Berkel

11. Greatest Common Divisor
gcd: main proc (ab?chan <<byte,byte>> & c!chan byte). begin x,y: var byte | forever do ab?<<x,y>> ; do x<y then y:= y-x or x>y then x:= x-y od ; c!x od end
GCD ab c
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Kees van Berkel

12. Nacking Arbiter
nack: main proc (a?chan bool & b!chan bool). begin na,nb: var bool | <<na,nb>> := <<true,true>> ; forever do sel probe(a) then a!nb || na:= na#nb or probe(b) then b!na || nb:= nb#na les od end
Nacking
arbiter a b
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Kees van Berkel

13. C : Tangram  handshake circuit a b
C(T) = ;  a c S R
C(R;S)=
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Kees van Berkel

14. C : Tangram  handshake circuit;  a c S R
C(R;S)= a c S R ; 
C(R;S)= | b
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15. C : Tangram  handshake circuit||   o | rx i
C (R||S) =
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16. Tangram Compilation Theorem
Tangram program T
Handshake circuit
VLSI circuit C E
Handshake process H ||
 · H · T = || · C ·T
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Kees van Berkel

17. 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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Kees van Berkel

18. 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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Kees van Berkel

19. Tangram program “Conway”b Q c R d
B1 = type [0..1] & B2 = type <<B1,B1>> & B3 = type <<B1,B1,B1>> & 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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Kees van Berkel

20. 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!<<x,y,z>> od end
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Kees van Berkel

21. Lab work: assignments 1 and 2
Assignment 1: shift registers
Assignment 2: fifos
See separate handout.
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Kees van Berkel

22. 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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Kees van Berkel

23. 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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Kees van Berkel

24. Next time: lecture 6 (2005, Oct 17)
Outline:
Tangram: arithmetic & resource sharing
Lab work: assignments on arithmetic & resource sharing
7/29/2019
Kees van Berkel