Ruby-VPI is a Ruby interface to IEEE 1364-2005 Verilog VPI
and a platform for unit testing, rapid prototyping, and
systems integration of Verilog modules through Ruby. It
lets you create complex Verilog test benches easily and
wholly in Ruby.
• See http://ruby-vpi.rubyforge.org for details.
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Version 19.0.0 (2007-08-27)
This release restores support for Cadence NC-Sim, breaks
support for Mentor Modelsim, adds support for concurrent
processes which simplify implementing Ruby prototypess, and
offers numerous other improvements.
Mentor Modelsim users, take note: this release does not
work very well with Mentor Modelsim, so do not upgrade
until compatibility is restored in a future release. In the
mean time, consider using this release with another
simulator, such as GPL Cver.
Thanks
• Calvin Wong requested the concurrent processes feature,
helped test it, and provided useful feedback.
Caution
• Prototypes no longer have a feign! method. Instead,
they emulate the behavior of the real Verilog DUT using
the new concurrency model.
• All “initial†blocks in Verilog code are now evaluated
before the specification begins executing. This allows
you to set the initial value of registers in Verilog
before the specification interacts with them.
• The Vpi module has been renamed to VPI for consistency
with the project name.
• The VPI::simulation_time method has been renamed to
VPI::current_time.
• The VPI::Handle.value_forced? method has been renamed
to VPI::Handle.force?
• The samp/ directory has been renamed to examples/.
• Code coverage analysis results are now produced only in
plain-text format.
Repairs
• You can now access VPI constants using their original
uncapitalized names. For example, you can now write
“vpiIntVal†instead of having to write “VpiIntValâ€.
However, note that the capitalized names are still
supported, so you are not required to change your code.
• Value change / edge detection for VPI handles was
previously incorrect: if you called the
VPI::Handle.posedge? function twice in the same time
step, it would give you two different answers.
• The problem of not being able to write values to nets
in Cadence NC-Sim has been fixed.
Additions
• Added support for concurrent processes, which make Ruby
prototypes appear more like Verilog code and also give
the ability to write parallel tests.
• Added support for performance profiling using the
ruby-prof project. The profiler can be enabled by
setting the PROFILER environment variable to “1†before
running a Ruby-VPI test.
• Added new method aliases to VPI::Handle for value
detection. The complete list of aliases is now:
â–¡ Tests if the logic value of this handle is unknown (x).
☆ x?
☆ unknown?
☆ dont_care?
â–¡ Sets the logic value of this handle to unknown (x).
☆ x!
☆ unknown!
☆ dont_care!
â–¡ Tests if the logic value of this handle is high
impedance (z).
☆ z?
☆ hi_z?
☆ high_z?
☆ high_impedance?
☆ tri_state?
☆ floating?
â–¡ Sets the logic value of this handle to high
impedance (z).
☆ z!
☆ hi_z!
☆ high_z!
☆ high_impedance!
☆ tri_state!
☆ floating!
â–¡ Tests if the logic value of this handle is at
“logic high†level.
☆ high?
☆ one?
â–¡ Sets the logic value of this handle to “logic highâ€
level.
☆ high!
☆ one!
â–¡ Tests if the logic value of this handle is at
“logic low†level.
☆ low?
☆ zero?
â–¡ Sets the logic value of this handle to “logic lowâ€
level.
☆ low!
☆ zero!
• Added new methods to VPI::Handle for value change /
edge detection:
□ edge? – detects positive and negative edges
□ change? – detects any kind of value change
□ change_00? – detects a value change from 0 to 0
□ change_01? – detects a value change from 0 to 1
□ change_0x? – detects a value change from 0 to unknown
□ change_0z? – detects a value change from 0 to high-Z
□ change_10? – detects a value change from 1 to 0
□ change_11? – detects a value change from 1 to 1
□ change_1x? – detects a value change from 1 to unknown
□ change_1z? – detects a value change from 1 to high-Z
□ change_x0? – detects a value change from unknown to 0
□ change_x1? – detects a value change from unknown to 1
□ change_xx? – detects a value change from unknown to unknown
□ change_xz? – detects a value change from unknown to high-Z
□ change_z0? – detects a value change from high-Z to 0
□ change_z1? – detects a value change from high-Z to 1
□ change_zx? – detects a value change from high-Z to unknown
□ change_zz? – detects a value change from high-Z to high-Z