NAME
|
proof |
− Formal proof between two behavioural descriptions |
SYNOPSIS
proof [-a] [-d] file1 file2
DESCRIPTION
Made to run on
a data-flow description, proof supports the same
subset of VHDL as asimut and boom and boog (for further
informations about this subset, please call the VHDL
manual). proof uses a Reduced Ordered Binary Decision
Diagrams representation that permits the designer to prove
easily the functionnal equivalence between two behavioral
descriptions. proof is generally used in order to
compare a behavioural specification with an extracted
behaviour obtained by yagle.
In default mode, a collapsing phase is done on the
description by removing all the auxiliary signals (the BDD
of the outputs, the registers and the buses are described
from the inputs or the registers). The two descriptions must
contain the same ressources (signals register with the same
name). It is possible to use the .inf file in
yagle (see further remark about YAGLE in this
document) to rename the registers in the extracted
behavioural description (see man yagle). The datas
and the commands (the guarded expressions) must match
separatly. The buses corresponding to completely specified
logical functions are represented by a logical multiplexor
in both descriptions. The two descriptions must have the
same interface (VHDL entity), if they do not, the formal
proof is stopped.
proof only uses two system environment variables related
to the work directory.
ENVIRONMENT VARIABLES
MBK_WORK_LIB gives the path for the behavioral descriptions. The default value is the current directory.
MBK_CATA_LIB gives some auxiliary pathes for the behavioral descriptions. The default value is the current directory.
OPTIONS
Options may be given in any order before the filenames.
−a This option asks proof to keep the common auxiliary signals. proof keeps all intermediate signals that have the same name in both descriptions (A common signal is considered as an input and an output of each description). This option can be useful for descriptions containing large equations. It may be used when proof has failed or if you want to debug in step by step mode the two different descriptions.
−d The program displays errors when the behavioral descriptions are different. Equations are displayed when it’s possible.
EXAMPLE
proof -a -d adder1 adder2
YAGLE
YAGLE (Functional abstraction) is now comercially distributed by Avertec (http://www.avertec.com/). More information can be obtained at their web site. Binaries of this tool can also be downloaded for non-commercial university research.