S1X70000 Datasheet, PDF (35/379 Pages) Epson Company – STANDARD CELL / EMBEDDED ARRAY

Chapter 2 Estimating the Gate Density
2.2.2 Estimating the Number of Gates Used in Basic Cell-Type MSI Cell
Before the number of gates used in the S1K/S1X70000-series Basic Cell-type MSI cell can
be estimated, the following pieces of information must be available.
• Circuit size
: G0 (gate or BC)
• Maximum operating frequency in the circuit : f (MHz)
• Percentage of circuit operating at f MHz
: α (%)
• Number of metalizations used
:M
The rules for reinforced power supplies are determined from the above information
(depending on the width of the reinforced power-supply line, one of two sets of rules
applies). Because no logic circuits can be placed below reinforced power supplies, the
area required for reinforced power supplies must be added to the above circuit size, G0
gates. Here, the necessary BC count, GA, where reinforced power supplies are considered,
is defined as
GA = G0 + (area required for the reinforced power supply) .... (1)
Further, the following is defined.
G0 / GA = β (%) Effective gate rate .... (2)
The effective gate rates are summarized in Tables 2-2 and 2-3.
Table 2-2 Effective Gate Rates (1 BC)
Metalization
Circuit
Layers
Percentage
50
Operating Frequency (MHz)
75
100
125
150
175
40%
89.4
87.7
84.6
—
—
—
AL3 layered
60%
88.3
85.6
80.2
—
—
—
80%
87.1
83.3
—
—
—
—
40%
90.9
90.3
89.8
89.3
88.7
88.0
AL4 or 5
layered
60%
80%
90.4
89.7
88.9
88.0
87.1
86.3
90.0
89.0
87.9
86.8
85.6
84.0
100%
89.6
88.3
86.8
85.6
84.0
82.5
40%
91.2
90.9
90.6
90.3
90.0
89.7
AL6 layered
60%
80%
90.9
90.5
90.0
89.6
89.1
88.6
90.7
90.1
89.5
88.9
88.3
87.7
100%
90.4
89.7
89.0
88.1
87.3
86.6
Note: Combinations left blank in the above table are not available.
(%)
200
—
—
—
87.5
85.1
83.3
80.2
89.3
88.1
86.8
85.6
STANDARD CELL S1K70000 SERIES
EPSON
27
EMBEDDED ARRAY S1X70000 SERIES