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CHAPTER 10 - ANALYSIS SYNTAX
Minbreak
speeds up
Transmission
line simulations.
MINSTEP=x
Default=none
Example: MINSTEP=1n
The value of MINSTEP is used as the minimum time at which the
internal data is accumulated during a simulation. Since the
internal data is determined by the activity of the circuit and not the
.TRAN statement, the “snap” turn off of a diode during a power
simulation can cause data to be collected at frequencies which
are much higher than the frequency of interest. MINSTEP is used
to reduce the extraneous data collected internally and reduce the
amount of memory used by a simulation. When setting MINSTEP,
please note that the higher frequency data will be folded into the
new sampling interval and appear as lower frequency oscillation.
Try using
MINBREAK=-1
to reduce
memory use if
you are not
using
transmission
lines.
MINBREAK=x Default=off
Example: Minbreak=5N
Sets the minimum time between transient breakpoints. Minbreak
is used to speed up the simulation of circuits which contain ideal
transmission lines. Increasing the minbreak time will speed up the
simulation at the expense of accuracy. For adequate accuracy
and best speed, it is recommended that the minbreak value be set
to about 1/4 of the time of the smallest transmission line delay. The
method used to simulate circuits using ideal transmission lines
has been completely changed from the process used in SPICE 2.
The result is greatly increased speed and much smaller memory
usage. The minbreak value can be used to further increase the
speed of the analysis.
*If MINBREAK is set to -1, IsSpice4 will not save any time
information prior to the value set for TSTART on the .TRAN line.
For long delayed simulations, this will reduce the amount of
memory used by a simulation. If the simulation contains transmission lines, this parameter should not be used.
MULTITHREAD=x Default=1
Example: Multithread=2
The number of multithreaded circuits.
NOISETEMP
Default=off
Example: Noisetemp
If .NOISETEMP is set, then overall circuit temperature is used
in noise calculations. Otherwise, each part’s individual
temperature is used in the NOISE calculation.
NOOPITER
Default Flag State=Off
Causes the simulation to go directly to gmin stepping and bypass
the standard operating point routine.
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