.\" /*
.\"  * Revision Control Information
.\"  *
.\"  * $Source: /vol/opua/opua2/sis/sis-1.1/common/src/sis/sis_lib/help/RCS/power_estimate.1,v $
.\"  * $Author: sis $
.\"  * $Revision: 1.2 $
.\"  * $Date: 1992/05/06 19:04:01 $
.\"  *
.\"
.XX
power_estimate [-m c] [-d c] [-t c] [-s c] [-a n] [-e f] [-n n]
               [-f file] [-S] [-M n] [-N n] [-R] [-h] [-v]

.PP
Estimates the power dissipated in a circuit due to switching activity:
.nf
        P = 0.5 x Vdd^2 x sum(p x C ) / f
                           i   i   i
where

        Vdd = 5V
        f = 20MHz
        p = expected number of transitions of node i in one clock cycle
         i
        C = capacitive load of node i
         i
.fi

The expected number of transitions of each node per clock cycle is
calculated through symbolic simulation, based on the static
probabilities of the primary inputs (by default prob_one = prob_zero =
0.5). The capacitive load of a node is obtained by summing the gate
capacitances of its fanout nodes and adding some internal drain
capacitance. Gate capacitances are multiple of a minimum sized
transistor (0.01pF), admitting transistor sizing based on the number
of inputs to the node (up to a value max_input_sizing, default
4). Drain capacitances are calculated from the number of transistors
this node has (multiple of 0.005pF) and this number can be obtained
either from a factored form or sum of products.

.PP
\fB-m c\fR Estimation mode, c either SAMPLING or BDD (default).

.PP
\fB-d c\fR Delay model, c one of ZERO (default), UNIT or GENERAL (from
library).

.PP
\fB-t c\fR Estimation type, c one of COMBINATIONAL (default),
SEQUENTIAL, PIPELINE or DYNAMIC (for dynamic domino circuits).

.PP
\fB-s c\fR PS lines probability calculation method, c one of APPROXIMATE
(default), EXACT or UNIFORM (0.5 is used). Only used for SEQUENTIAL
type.

.PP
\fB-a n\fR Number of PS lines to be correlated (default 1). Only used
for the APPROXIMATION method.

.PP
\fB-e f\fR Maximum error allowed for PS lines probabilities (default
0.01). Only used for the APPROXIMATION method.

.PP
\fB-n n\fR Number of sets of 32 input vectors to be simulated (default
100). Only used for SAMPLING mode.

.PP
\fB-f filename\fR Allows the specification of input probabilities, node
capacitances and node delays in the format:

.nf
                name "nodename" p0 "value"
                name "nodename" p1 "value"
                name "nodename" cap_factor "value"
                name "nodename" delay "value"
.fi

.PP
\fB-S\fR Assumes complex gates in sum of products form (default is factored
form).

.PP
\fB-M n\fR Maximum number of inputs of a node considered for transistor
sizing (default 4).

.PP
\fB-N n\fR Interval of input vectors for which the current value of
power estimation is printed. Only used for SAMPLING mode.

.PP
\fB-R\fR Sets latch capacitances to 0, only comb power reported.

.PP
\fB-h\fR Prints power_estimate usage.

.PP
\fB-V n\fR Verbose run time information.

Note: currently a memory fault occurs on the RS6000 when the exact calculation
is used for present state probabilities.  This is probably due to the use
of stg_extract. 
