Information Technology Reference
In-Depth Information
All distances are in lambda ( l ) design rules. The following assumptions also
apply to the mathematical model:
The process allows stacked contacts (stacked vias).
Placement issues are not taken into account; every window is used by one
connection to/from the core under study.
Metal layer n is the highest metal layer in the process.
The metal layers below m are used for local interconnections inside the core.
The metal layers from m+1 to n are used to connect outside the core.
These dimensions are shown in Figure 17.9.
The number of connections possible to a core C with area H H,canbe
computed with Equations 17.6 to 17.8 [80]. Equation 17.6 computes the maximum
number of possible connections on metal layer j.
4
5
H 2 E þ P
j 1
i ¼ 1 ð D i þ L i Þ D j
C j ¼ 4
ð 17
:
6 Þ
D j þ S j
The inequality shown in Expression 17.7 ensures that there is enough space in
the center of the core to continue adding rings of windows.
"
# 4 0
H 2 E þ X
j 1
i ¼ 1 ð D i þ L i Þ
ð 17
:
7 Þ
S1
W1
W1
W1
W1
W1
W1
W1
W1
W1
D1
L1
S2
W2
W2
W2
W2
W2
W1
W1
E
D2
L2
W1
W1
S3
W2
W3
W2
W3
W1
W1
D3
Figure 17.9. The model parameters.
 
Search WWH ::




Custom Search