Average energy per
packet (nJ)
0
2
4
6
8
WH
VC
0.0
0.3
0.5
0.8
Locality factor
108
Network-on-Chip
Figure 4.35
Comparison of average packet energy at saturation under different locality factors in both
WH- and VC-based MoT networks.
TABLe 4.9
Area Required for Each Type of WH and VC Routers for Designing a
MoT-Based NoC
Type-1 Router
Type-2 Router
Type-3 Router
Area
Area
Area
Router
Position
(mm 2 )
Position
(mm 2 )
Position
(mm 2 )
WH
Leaf
0.057
Stem
0.041
Root
0.022
VC
Leaf
0.183
Stem
0.18
Root
0.08
TABLe 4.10
Area Overhead for 32- and 256-Core MoT-Based NoCs with WH and VC Routers
32 Cores
256 Cores
Overall Area
Overall Area
Router
(mm 2 )
Overhead (%)
(mm 2 )
Overhead (%)
WH
223.6
11.8
1800.12
12.5
VC
247.7
23.85
2006.57
25.4
under uniformly distributed and localized traffic. It can be observed that
the energy per packet in a VC-based network is higher than in a WH-based
network for all locality factors.
4.7.4 Area required
The silicon area required for leaf, stem, and root routers of MoT network in
both WH and VC schemes is shown in Table  4.9. As described in Section
4.6.1, only the stem routers of the column trees of each 2 × 2 MoT subnetwork