.\" $Id: asimut.1,v 220.127.116.11 2002/04/04 15:44:24 ludo Exp $
.\" @(#)asimut.1 1.92 Nov 30 1995 UPMC; Pirouz BAZARGAN SABET
.TH ASIMUT 1 "October 1, 1997" "ASIM/LIP6" "cao\-vlsi reference manual"
\fBasimut\fP \- A simulation tool for hardware descriptions
asimut \fI[options] [root_file] [pattern_file] [result_file]\fP
\fBasimut\fP is a logical simulation tool for hardware descriptions. It
compiles and loads a complete hardware description written in VHDL (Very
high speed integrated circuits Hardware Description Language). The hardware
description may be structural (a hierarchy of instances) or behavioural.
Only a subset of VHDL is supported. Descriptions that do not
match this subset cause a syntax error during compilation. See \fBvhdl(5)\fP
for detailed information about the supported subset of VHDL.
Once a hardware description is loaded, \fBasimut\fP looks for a simulation
pattern description file. This file is to be written in \fBpat\fP format.
The file is compiled, loaded and linked with the hardware description. Then,
the simulation is started. When patterns are processed, a result file in
\fBpat\fP format is produced.
If a save action has been requested in the pattern description file (see
\fBpat (5)\fP), \fBasimut\fP creates also a save file representing the state
of the description at the end of the simulation of the last pattern. The save
file is named \fIroot_file\fP.sav, where \fIroot_file\fP is the name of the
The save file can be used in a later simulation sequence to initialize the
state of the (same) hardware description before the simulation begins.
Using this mechanism, a large sequence of patterns can be breaked onto
several small sequences, each one initializing the hardware description with
the save file resulted from the previous sequence.
\fBasimut\fP reads several parameters from the environment variables :
list of directories containing description and pattern files (using $PATH
syntax). The default path is the current directory (see mbk(1)).
specifies the current working directory. The working directory idicates the
place where all output files are written.
Indicates the file where the behavioral description files are listed. This
file is used to leaf cells of a structural description.(see mbk(1))
file extension for structural entity. (see mbk(1))
list of file extensions for behavioural entities (using $PATH syntax). The
default file extension is \fBvbe\fP.
list of file extensions for pattern description entities (using $PATH syntax).
The default file extension is \fBpat\fP.
list of file extensions for delays description entities (using $PATH syntax).
The default file extension is \fBdly\fP.
maximum number of errors allowed during simulation phase. If the number of
errors occured during simulation reaches VH_MAXERR, \fBasimut\fP stops
the simulation at the end of processing the current pattern. Patterns following
the current pattern remain unprocessed and are reproduced in the result file.
The default value of \fIVH_MAXERR\fP is 10.
\fIroot_file\fP is the name of the description.
By default \fBasimut\fP looks for a structural description. It uses the
\fIMBK_IN_LO\fP environment variables to identify both the format and the
extension of structural description files. To load structural VHDL files
\fIMBK_IN_LO\fP must be set to \fBvst\fP.
To load a pure behavioural description \fB\-b\fP option must be specified. In
such a case \fBasimut\fP loads a data flow VHDL description file. The
\fIVH_BEHSFX\fP environment variable gives the extensions to be used.
\fIpattern_file\fP is the entity name of the pattern description. The file
containing this entity must be named \fIpattern_file.ext\fP , where \fIext\fP
is one of the extension specified in \fIVH_PATSFX\fP.
\fIresult_file\fP is the result file produced by \fBasimut\fP. The result file
is a pattern description file with the extension specified by \fIVH_PATSFX\fP.
consider the \fIroot_file\fP description as a behavioural description
\fI\-backdelay [min, max, typ] delay_file\fP
use file \fIdelay_file.ext\fP for delays backannotation, where \fIext\fP
is one of the extension specified in \fIVH_DLYSFX\fP.
use BDDs (Binary Decision Diagram) to represent expressions. Using this option
makes the simulation be two times faster but increases memory requirement
run only the compilation stage
at the first error encountered, dump the state of the circuit in both an
ascii file (suffixed .cor) and a binary save file (suffixed .sav) which can
be used as initialization file in a further session. If the \fI\-nores\fP
option is specified a pattern file is also produced.
call the debugger (developper usage)
only null delays (no after clause in the VHDL file) are changed if
backannotated delays or fixed delays are specified.
\fI\-fixeddelay value (\-fd value)\fP
all delays of the description are fixed to \fIvalue\fP.
display this help file
initialize all signals of the description with \fIvalue\fP. \fIValue\fP can
be 0 or 1
read a save file and use it to initialize the state of the description before
processing the first pattern (the file name cannot be 1 nor 0)
produce a pattern file corresponding to the interface of the instance
identified by \fIinstance-name\fP
print at most \fIn\fP characters for pattern labels. The default value for
\fIn\fP is 15.
do not generate result file
load at most \fIn\fP patterns from input pattern file each time. Using this
feature reduces memory allocation when a great number of patterns are to be
simulated. In addition after the \fIn\fP patterns have been processed, the
simulation result is printed in the result pattern file. The default value
for \fIn\fP is 0 which makes the whole pattern
file be loaded.
trace signals when making BDDs (developper usage).
use transport delay model (default is inertial).
all the delays of the VHDL description are supposed to be null delays.
asimut \-b \-i init_add adder_32 adder_patterns res_add
simulates a behavioural description held in the file named 'adder_32.vbe
using the pattern file `adder_patterns.pat'. The simulation results is
written into 'res_add.pat' and the description is initialized with the
values contained in 'init_add.sav'.
Register initializations in the pattern file allows changing the value of
a register into a known value. However, using this feature to initialize a
register before executing the first pattern is not recommended. Registers
value (defined by the initialization statement) may be overwritten since
description has not a coherent state before the first pattern.
.SH SEE ALSO
vhdl(5), pat(5), genpat(1), mbk(1)