Network-on-Chip ????

1
Network-on-Chip ????
Fat H-Tree ??????????

• ?? ?? (??)
• ?? ?? (NII)
• ?? ?? (??)

2
Network-on-Chip (NoC) ???
??????????????
(VDEC/ASPLA/?? 90nm CMOS)
3
NoC ????? Mesh Torus

• 2-D Mesh

• 2-D Torus
• ?????2????

Dally, DAC01
RAW Taylor, IEEE Micro02
aSOC Liang, IEEE TVLSI04
Fat H-Tree ???????????????, ?????????????
???
????
4
NoC ????? Fat Tree
SPIN Andriahantenaina, DATE03
p ??????? q ??????? c ???????

• Fat Tree (p, q, c)

SCORE Caspi, FPL00
ACM Furtek, FPL04
Rank-1
Rank-2
Fat Tree (2,4,2)
Fat Tree (2,4,1)
Fat Tree ? Fat H-Tree ???????????, ??????????????
???
????
5
?????

• NoC ?????
• Mesh, Torus
• H-Tree, Fat Tree
• Fat H-Tree ???
• ??
• ????? (2??, 3??)
• ?????? (DTR)
• Fat H-Tree ???
• ??????
• ???????
• ??????

6
Fat H-Tree ??

• Fat H-Tree
• Red Tree (H-Tree)
• Black Tree (H-Tree)

??, ???06
2??H-Tree (red black) ???
Black Tree?Red Tree??????????, Fat Tree
????????????
???
????
???
????
7
Fat H-Tree ??

• Fat H-Tree
• Red Tree (H-Tree)
• Black Tree (H-Tree)

Yamada, EUC04
2??H-Tree (red black) ???
Fat H-Tree ? Red Tree ? Black Tree ??????
???
????
???
????
8
Fat H-Tree ??

• Fat H-Tree
• Red Tree (H-Tree)
• Black Tree (H-Tree)

Yamada, EUC04
2??H-Tree (red black) ???
Fat H-Tree ? Red Tree ? Black Tree ??????
???
????
???
????
9
Fat H-Tree ??

• Fat H-Tree
• Red Tree (H-Tree)
• Black Tree (H-Tree)

Yamada, EUC04
2??H-Tree (red black) ???
Fat H-Tree ? Red Tree ? Black Tree ??????
???
????
???
????
10
Fat H-Tree ??

• Fat H-Tree
• Red Tree (H-Tree)
• Black Tree (H-Tree)

Yamada, EUC04
2??H-Tree (red black) ???
?????? Red tree, Black tree ?????????
??? rank-2 ?????????
???
????
???
????
11
Fat H-Tree 2???????

• Fat H-Tree
• ?????????
• ? ????????? (2???????????)

??????????????????
??????????
Fat H-Tree ?2???????
???
????
12
Fat H-Tree 3????????

• ????, ???????
• ??????? ? ???????
• ????3????
• ?????????(??????)???

??????????
Davis,DToC05
???4?????? (?????)
???1?????? (?????)
13
Fat H-Tree 3???????

• Fat H-Tree ?4??
• ?????????
• ????????????????????

(Red Tree Black Tree)

1. ???????
2. ???????

14
Fat H-Tree 3???????

• Fat H-Tree ?4??
• ?????????
• ????????????????????

(Red Tree Black Tree)

1. ???????
2. ???????

15
Fat H-Tree 3???????

• Fat H-Tree ?4??
• ?????????
• ????????????????????

(Red Tree Black Tree)

1. ???????
2. ???????

16
Fat H-Tree ????????????

• ??????????
• Red Tree ????, or
• Black Tree ????

17
Fat H-Tree ????????????

• ??????????
• Red Tree ????, or
• Black Tree ????

• ???????????
• ?????????
• ????

?????????????????????????????
????!
18
Fat H-Tree Dual tree routing (DTR)

• Dual tree routing
• ???????????
• ???????????
• ? Deadlock ??

• Deadlock ???
• Red Tree??Black Tree ????????, ????????? 1

VC0 ???
????!
VC1 ???
64??? Fat H-Tree ????????????????? 2?
19
?????

• NoC ?????
• Mesh, Torus
• H-Tree, Fat Tree
• Fat H-Tree ???
• ??
• ????? (2??, 3??)
• ?????? (DTR)
• Fat H-Tree ???
• ??????
• ???????
• ??????

20
????????? Channel bisection
N16 N64 N256
HT 4 4 4 4
FT1 8 16 32
FT2 16 32 64
FHT 24 40 72
Mesh 8 16 32
Torus 16 32 64
FT1 Fat Tree(2,4,1) FT2 Fat Tree(2,4,2)
Fat H-Tree ?, ?????????????????????
21
?????? ??????
N16 N64 N256
HT 5 21 85
FT1 6 28 120
FT2 12 56 240
FHT 10 42 170
Mesh 16 64 256
Torus 16 64 256
FT1 Fat Tree(2,4,1) FT2 Fat Tree(2,4,2)
?????? Network Interface (NI) ??? Fat H-Tree ????
2-port ? NI ???
Fat H-Tree ?????? Fat Tree(2,4,2) ????? ? ??(?)
22
?????? NoC ???

• ???? NI ???
• 16??, 64??
• Design Compiler
• 0.18um CMOS
• ??????
• 32-bit Wormhole
• 4???????
• ??????2?
• NI ???
• ??? 2-flit FIFO
• ??? 2-flit FIFO

2VCs
Buf
Buf
2VCs
Buf
Buf
Input Ports
Crossbar
???? Wormhole Router ???
??, SACSIS06
Fat H-Tree ? NI ??????????? ? Fat H-Tree ? NI ?
router ?????
23
?????? ???? (16 / 64??)
???? (16??)
Fat H-Tree ? NI ??????????
???? (64??)
Fat H-Tree ? NI ?????, ???? Fat Tree(2,4,2) ???(?)
24
??? ???????? 1-Unit

• ? Unit ?
• ?????????
• ??? ?????

???? Unit ??
1-Unit ?
1-Unit ???????
N16 N64 N256
HT 24 112 480
FT1 32 192 1,024
FT2 64 384 2,048
FHT 72 392 1,800
Mesh 24 112 480
Torus 48 224 960
1-Unit ?
Fat H-Tree ??????????, Fat Tree(2,4,2) ?????
FT1 Fat Tree(2,4,1) FT2 Fat Tree(2,4,2)
25
??????? NoC??????

• ?????????
• 1-flit ???????
• ???????????

• ??????????
• 12mm???? (16 / 64??)
• 0.18um CMOS
• ???????
• 1-bit ?? _at_ ???(NI)
• ?????????????? (Power compiler)
• 1.88 pJ / hop
• 1.27 pJ / hop
• 1.45 pJ / hop
• ???????
• 1-bit ?? _at_ ???
• 0.67 pJ / mm

12mm
for routers
for NI
for NI(FHT)
Wang, DATE05
26
??????? ???? (16 / 64??)
?????????? (16??)
?????????? (64??)
Fat H-Tree ????????? Fat Tree(2,4,2) ?????
27
???? ??????????

• ??????????????
• ?????? vs. ??
• 16??, 64??
• ???? (??????)
• Mesh, Torus (DOR)
• Fat Trees (up/down)
• Fat H-Tree (DTR)

• ??????????
• Uniform
• BT.W
• SP.W
• CG.W
• MG.W
• IS.W

??????? 16-flit (1-flit header)
??????? 1-flit per channel
?????? Wormhole switching
??????? 2
???? 3-cycle per 1-hop
NAS Parallel Benchmark
28
FHT vs. Fat Tree Uniform (16 / 64??)

• Fat H-Tree (FHT)
• Fat Tree(2,4,2)
• Fat Tree(2,4,1)

FHT (DTR) ?????????????????????
Uniform (16??)
Uniform (64??)
16???? FHT ? Fat Tree ??????, 64???? FHT ??
29
FHT vs. Fat Tree BT (16 / 64??)

• Fat H-Tree (FHT)
• Fat Tree(2,4,2)
• Fat Tree(2,4,1)

FHT(DTR) ??, ?????????????????
BT ?????? (64??)
BT ?????? (16??)
???????? BT ????????, FHT ? 64??????
30
FHT vs. Fat Tree MG (16 / 64??)

• Fat H-Tree (FHT)
• Fat Tree(2,4,2)
• Fat Tree(2,4,1)

MG ?????? (16??)
MG ?????? (64??)
BT??, MG ??????????? FHT ? Fat Tree ??????
31
Fat H-Tree ????

• ??????????
• Dual Tree Routing
• VLSI ?????
• 2???????
• 3???????
• Fat H-Tree ???
• ?????? Uniform ????????? Fat Tree ?????
• ?????? Fat Tree (2,4,2) ?? 20.528.1 ???
• ??????? Fat Tree (2,4,2) ?? 6.77.0 ???
• ????? Fat Tree (2,4,2) ????