Timing%20Abstraction

1
Timing Abstraction
Pirouz Bazargan Sabet
Patricia Renault
Dominique Le Dû
2
Abstraction
Netlist Tr, C, R
Functional Abstraction
Netlist of Gates, C, R
Timing Abstraction
Gate Del ays
3
Functional Abstraction
follow the current paths
Fdown a
. b
4
Functional Abstraction
Fup db
ca
c
Fdown db
ca
conflict
a
d
tri-state
b
functional view ¹ timing view
5
Delay Evaluation
Accurate delay using electrical simulation
Simulation of each configuration 1 input
switching while others are in steady state
6
Delay Evaluation
Fup db
ca
c
Fdown db
ca
a
d
b
7
Delay Evaluation
sources of correlation
Include the gates until reaching the sources of
correlation

• size

• some correlations are not useful

• number of configurations

8
Delay Evaluation
sources of correlation
Explore the supergate to identify the
configurations to be simulated
Functional exploration
9
Delay Evaluation
Fup db
ca
c
Fdown db
ca
a
d
a
b
c
d
b
x
x
x
x
x
x
x
x
x
x
x
x
10
Delay Evaluation
Functional correlation
a
b
inputs
configs
timing correlation
transition delay between a and b depends on the
delay of the gates involved in the supergate
Electrical simulations should be done regarding
the gates graph
11
Delay Evaluation
Timing dependency