Functional Coverage and Constrained Randomization Extensions for Cocotb
This package allows you to use constrained randomization and functional coverage techniques known from CRV (constrained random verification) and MDV (metric-driven verification) methodologies, available in SystemVerilog or e. Such extensions enable the implementation of an advanced verification environment for complex projects.
The implemented functionality is intended to be easily understandable by SystemVerilog users and provides significant extensions compared to Hardware Verification Languages.
There is an option to export coverage database to a readable XML or YML format and a function which allows for merging such files is provided.
The package can be installed with pip. Version 1.2.0
is the latest one and recommended.
pip install cocotb-coverage
# point represented by x and y coordinates in range (-10,10)
class Point(crv.Randomized):
def __init__(self, x, y):
crv.Randomized.__init__(self)
self.x = x
self.y = y
self.add_rand("x", list(range(-10, 10)))
self.add_rand("y", list(range(-10, 10)))
# constraining the space so that x < y
self.add_constraint(lambda x, y: x < y)
...
# create an arbitrary point
p = Point(0,0)
for _ in range (10):
# cover example arithmetic properties
@CoverPoint("top.x_negative", xf = lambda point : point.x < 0, bins = [True, False])
@CoverPoint("top.y_negative", xf = lambda point : point.y < 0, bins = [True, False])
@CoverPoint("top.xy_equal", xf = lambda point : point.x == point.y, bins = [True, False])
@CoverCross("top.cross", items = ["top.x_negative", "top.y_negative"])
def plot_point(point):
...
p.randomize() # randomize object
plot_point(p) # call a function which will sample the coverage
# export coverage to XML
coverage_db.export_to_xml(filename="coverage.xml")
# export coverage to YAML
coverage_db.export_to_yaml(filename="coverage.yml")