Non-slicing Floorplanning-based Crosstalk Reduction on Gridless - - PowerPoint PPT Presentation

▶
non slicing floorplanning based crosstalk reduction on
SMART_READER_LITE
LIVE PREVIEW

Non-slicing Floorplanning-based Crosstalk Reduction on Gridless - - PowerPoint PPT Presentation

Apr 14, 2023 126 likes •455 views

Non-slicing Floorplanning-based Crosstalk Reduction on Gridless Track Assignment for a Gridless routing System with Fast Pseudo-Tile Extraction Yu-Ning Chang Yih-Lang Li Wei-Tin Lin Wen-Nai Cheng Dept of CS, National Chiao Tung University,

slide-1
SLIDE 1

1

Non-slicing Floorplanning-based Crosstalk Reduction on Gridless Track Assignment for a Gridless routing System with Fast Pseudo-Tile Extraction

Yu-Ning Chang Yih-Lang Li Wei-Tin Lin Wen-Nai Cheng

Dept of CS, National Chiao Tung University, Hsinchu, Taiwan

slide-2
SLIDE 2

2

Outline

Introduction

Crosstalk-Driven GTA Detailed Routing Experimental Results Conclusion

slide-3
SLIDE 3

3

Why Gridless and Crosstalk- Driven Router ?

Crosstalk induced by adjacent wires

increases the coupling capacitance and delay

  • f the wires.

In modern designs, variable-width and

variable-space routing is commonly used for the purpose of crosstalk and delay

  • ptimization

Gridless routers are more flexible for

variable-rule routing than grid-based routers

slide-4
SLIDE 4

4

Preliminaries

IRoute 1 IRoute 2 IRoute 3 Pin Pseudo pin

slide-5
SLIDE 5

5

Preliminaries

i1 i2 i3 i5 i7 i6 i4 sub-panel Horizontal panel Vertical panel Cut line

slide-6
SLIDE 6

6

Preliminaries

Crosstalk Model f is switching factor l is coupling length d is distance β

α

j i j i j i c

d l f j i C

, , ,

) , ( ⋅ ⋅ =

slide-7
SLIDE 7

7

Routing Flow

GTA Preprocess: IRoute Extraction Initial GTA Sub-panel re-arrangement

Crosstalk reduction Gridless track assignment(GTA)

Global paths Gridless Detailed routing

Detailed routing

Track assignment results Detailed routing preprocess: Routing tree construction Global router Pattern routing Extended O-tree Floorplan Based Assignment refinement

slide-8
SLIDE 8

8

Contributions of this work

This work develops a complete crosstalk-

driven three-stage gridless routing system.

A congestion-driven global router A crosstalk-driven gridless TA (GTA) Enhanced NEMO with fast PMT extraction for

detailed router.

slide-9
SLIDE 9

9

Outline

Introduction

Crosstalk-Driven GTA

Detailed Routing Experimental Results Conclusion

slide-10
SLIDE 10

10

Crosstalk-Driven GTA

GTA Preprocess: IRoute Extraction Initial GTA Sub-panel re-arrangement

Crosstalk reduction

Extended O-tree Floorplan Based Assignment refinement

Gridless track assignment

slide-11
SLIDE 11

11

Initial GTA

19 14 16 11 15 12 18 10 2/13 9 17 5 2 3 1 4 7 6 8

slide-12
SLIDE 12

12

Crosstalk-Driven GTA

GTA Preprocess: IRoute Extraction Initial GTA Sub-panel re-arrangement

Crosstalk reduction

Extended O-tree Floorplan Based Assignment refinement

Gridless track assignment

slide-13
SLIDE 13

13

Extended O-Tree Based Assignment Refinement (EOBAR)

1 2 3 4 5 7 6 7 6 5 4 r 7 6 5 1 4 2 3 1 2 3 7 6 5 1 2 3 external insertion location 4 r internal insertion location

Overlap graph O-tree Extended O-tree

(a) (b) (c) (b) (d)

slide-14
SLIDE 14

14

Extended O-Tree Based Assignment Refinement

1 2 3 4 5 7 6 7 6 5 1 2 3 4 r 6 5 1 2 3 4 r 1 2 3 4 5 6

slide-15
SLIDE 15

15

Extended O-Tree Based Assignment Refinement

1 6 5 4 7 2 3 r 1 2 3 4 5 7 6 1 6 5 4 7 2 3 r 1 2 3 4 5 7 6

Infeasible

(c) (b)

7 6 5 4 1 2 3 r 1 2 3 4 5 7 6

(a)

1 2 3 4 5 6 7 1 6 5 4 7 2 3 r

(d)

slide-16
SLIDE 16

16

Insertion is realized by tentative plow

IRT: IRoute under test

IL: Insertion Location Plowing direction:

Extended O-Tree Based Assignment Refinement

A IL A IL B IRT IRT IRT A IL B B C IRT B C D IRT IRT

Type I: plow IRT path Type II: plow IRoute

  • verlap to IRT

Type III: plow effect propagation to neighboring path

A IRT IRT

slide-17
SLIDE 17

17

Crosstalk-Driven GTA

GTA Preprocess: IRoute Extraction Initial GTA Sub-panel re-arrangement

Crosstalk reduction

Extended O-tree Floorplan Based Assignment refinement

Gridless track assignment

slide-18
SLIDE 18

18

Sub-panel Rearrangement

1 4 6 3 9 11 2 5 8 12 10 7 HIR1 HIR2 HIR3 HIR4

4 1 2 3

20 22 14 34 14 14 13 37 7 12 20 20

1 4 3 9 5 8 6 11 2 12 10 7 HIR1 HIR4 HIR3 HIR2

1 2 3

14 13 12

4

slide-19
SLIDE 19

19

Outline

Introduction Crosstalk-Driven GTA

Detailed Routing

Experimental Results Conclusion

slide-20
SLIDE 20

20

Detailed routing

Gridless Detailed routing

Detailed routing

Track assignment results Detailed routing preprocess: Routing tree construction Pattern routing

slide-21
SLIDE 21

21

Routing Tree Construction

IRoute 1 IRoute 2 IRoute 3 Pin Pseudo pin

slide-22
SLIDE 22

22

Routing Tree Construction

IRoute 1 IRoute 2 IRoute 3 Pin Pseudo pin

slide-23
SLIDE 23

23

Detailed routing

Gridless Detailed routing

Detailed routing

Track assignment results Detailed routing preprocess: Routing tree construction Pattern routing

slide-24
SLIDE 24

24

Gridless Detailed Routing

1 1 1 1 2 2 2 2 2 3 3 3 3 4 4 4 5 5 5 6 7 7 7

P1 P2 P3

X Y Z A B C D PMT6 PMT7 PMT5 PMT2 PMT3

PMT1

S T

PMT4

slide-25
SLIDE 25

25

Bin-Based Data Structure and Fast PMT Extraction

Blockage Pseudo Block Un- routable Region

Bin-based data structure

Wire Block Global path

p2 p1 s t

slide-26
SLIDE 26

26

Experimental Results

All routing cases were conducted on a

1.2GHz Sun Blade-2000 workstation with 2GB RAM

Six MCNC benchmark circuits using three

routing layers

slide-27
SLIDE 27

27

Experimental Results

Table 1. Comparison of routing performance between NEMO and this work.

NEMO This work Fast PMT extraction Time (Tn:sec) Mem (MB) Time (Tt:sec) Mem (MB) s5378 2.4 10 2.10 22 s9234 1.7 9 1.45 21 s13207 6.6 15 4.43 25 s15850 8.8 18 6.51 27 s38417 37.2 48 13.46 37 s38584 73.7 66 30.52 45 Tn/Tt 1.72 1

slide-28
SLIDE 28

28

Experimental Results

Table 2. Statistics of crosstalk reduction for fixed- and variable-rule routings.

Initial assignment O-tree based refinement + HIR re- arrangement Coupling cap. x 103 (C1) Coupling cap. x 103 (C2) RR (%) Circuit FR VR FR VR FR VR S5378 .168 .123 .075 .091 55 26 S9234 .107 .086 .040 .047 63 46 S13207 .379 .294 .160 .205 58 30 S15850 .493 .363 .205 .275 59 24 S38417 1.013 .794 .385 .559 62 30 S38584 1.402 1.026 .578 .863 59 16 Ave. 59 29

slide-29
SLIDE 29

29

Experimental Results

Global Routing + NEMO Global Routeing + crosstalk driven GTA + fast PMT extraction NEMO Run time (sec) W.L. (×104μm ) Run time (sec) W.L. (×104μm ) FR VR FR VR FR VR FR VR s5378 2.4 3.74 7.4 7.6 1.70 2.31 8.0 8.2 s9234 1.7 2.69 5.5 5.6 1.25 1.72 6.0 6.1 s13207 6.6 11.28 17 18 4.13 7.62 19 19 s15850 8.8 16.33 22 22 5.34 8.33 23 24 s38417 37.2 56.36 48 49 14.04 15.75 52 52 s38584 73.7 143.39 67 68 22.65 27.64 72 72 Comp. 2.66 4.17 0.93 0.94 1 1 1 1

  • Table 3. Comparison of routing results between this work and [13].
slide-30
SLIDE 30

30

Experimental Results

Table 4. Comparison of fixed-rule routing results of a commercial routing tool and this work.

Run time (sec) Wire length (×104μm) Coupling capacitance (pf) circuit This work CR wt SI This work CR wt SI This work CR wt SI s5378 1.70 16 8.0 7.7 3.88 4.67 s9234 1.25 14 6.0 5.7 2.28 2.72 s13207 4.13 43 19 18 8.38 9.74 s15850 5.34 49 23 23 11.29 13.77 s38417 14.04 110 52 50 21.78 23.68 s38584 22.65 157 72 69 32.69 37.06 Comp. 1 7.92 1 0.96 1 1.17

slide-31
SLIDE 31

31

Conclusion

This work presents a three-stage gridless

routing system

Experimental results reveal that the proposed

gridless routing system can perform over 2.66 times faster than NEMO.

As compared with a commercial routing tool,

this work yields an average runtime speedup

  • f 7.92 times and an average 15% reduction

rate in coupling capacitance

slide-32
SLIDE 32

32

Thank you