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

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

Lecture 5 Outline: Recapitulation Lecture 4 Tangram overview Compilation: Tangram Handshake Circuits Tools Demonstration Lab work: assignment “fifos and registers” 7/29/2019 Kees van Berkel

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 7/29/2019 Kees van Berkel

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 7/29/2019 Kees van Berkel

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 7/29/2019 Kees van Berkel

Four 88 shift registers compared 7/29/2019 Kees van Berkel

Tangram/Haste Purpose: programming language for asynchronous VLSI circuits. Creator: Tangram team @ 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. 7/29/2019 Kees van Berkel

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 7/29/2019 Kees van Berkel

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 7/29/2019 Kees van Berkel

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 7/29/2019 Kees van Berkel

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 7/29/2019 Kees van Berkel

C : Tangram  handshake circuit  a b C(T) = ;  a c S R C(R;S)= 7/29/2019 Kees van Berkel

C : Tangram  handshake circuit ;  a c S R C(R;S)= a c S R ;  C(R;S)= | b 7/29/2019 Kees van Berkel

C : Tangram  handshake circuit ||   o | rx i C (R||S) = 7/29/2019 Kees van Berkel

Tangram Compilation Theorem Tangram program T Handshake circuit VLSI circuit C E Handshake process H ||  · H · T = || · C ·T 7/29/2019 Kees van Berkel

VLSI programming of asynchronous circuits behavior, area, time, energy, test coverage Tangram program feedback compiler simulator Handshake circuit expander Asynchronous circuit (netlist of gates) 7/29/2019 Kees van Berkel

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 7/29/2019 Kees van Berkel

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 7/29/2019 Kees van Berkel

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 7/29/2019 Kees van Berkel

Lab work: assignments 1 and 2 Assignment 1: shift registers Assignment 2: fifos See separate handout. 7/29/2019 Kees van Berkel

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. 7/29/2019 Kees van Berkel

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%] 7/29/2019 Kees van Berkel

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