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Describing Designs for VIS
VIS operates on an intermediate format called BLIF-MV, which is an
extension of BLIF, the intermediate format for logic synthesis
accepted by SIS [4]. VIS includes a stand-alone compiler
from Verilog to BLIF-MV, called VL2MV [3], which supports a
synthesizable subset of Verilog. VL2MV extracts a set of
interacting finite state machines that preserves the behavior of the
source Verilog program defined in terms of simulated results.
Two new features have been added to Verilog:
- 1.
- Nondeterminism.
A nondeterministic construct, $ND,
has been added
to specify nondeterminism on wire variables; this is
the only legal way to introduce nondeterminism in VIS. Internally,
$ND introduces pseudo-inputs which can non-deterministically
take any allowed value.
- 2.
- Symbolic variables.
Sometimes it is desirable to specify and examine the value of variables
symbolically, rather than having to explicitly encode them.
VL2MV extends Verilog to allow symbolic variables
using an enumerated type mechanism similar to the one available
in the C programming language.
Currently, a translator from a subset of VHDL to BLIF-MV is being
developed and a path from Esterel to BLIF-MV is available
through the POLIS system at Berkeley.
Next: Verification In VIS
Up: VIS
Previous: VIS Philosophy
Roderick Bloem
2001-05-21
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