# Registry¶

PyGears uses a centralized registry to share global data, like configuration, between its submodules. There is also a user API for manipulating the registry in order to provide some user configuration. Registryis organized as a large tree resembling the file system. Basically, there are two commands at users disposal:

bind(key_pattern, value)

Sets a new value for the registry location designated by key_path.

Parameters
• key_path – a UNIX style path without leading ‘/’

• value – value to set

Example - configure the simulator not to throw exeptions on simulation errors:

bind('logger/sim/error/exception', False)

registry(key_path)

Retrieves a value from registry at the location designated by key_path.

Parameters

key_path – a UNIX style path without leading ‘/’

Example - Obtain a list of directory paths where SystemVerilog generator will look for the SystemVerilog implementations of the gears:

>>> registry('svgen/sv_paths')
['/tools/home/.pygears/svlib', '/tools/home/pygears/pygears/common/svlib', '/tools/home/pygears/pygears/cookbook/svlib']


## Variables¶

• svgen: Data used by the SystemVerilog generation submodule

• svgen/flow: List of operations performed while generating a SystemVerilog code for the PyGears description. Flow configuration is usually not modified by the user, but can be used to implement a custom generation flow.

• svgen/sv_paths: List of directory paths where SystemVerilog generator will look for the SystemVerilog implementations of the gears. User can include additional direcrories where custom SystemVerilog files are located.

• debug_intfs: []

• sim:

• config

• gear: Data used by the gear instantiation submodule

• gear/naming:

• gear/naming/pretty_sieve (bool): Try to obtain a variable which was sliced to form a sieve. Turned off by default because it impacts performance on large designs.

• gear/naming/default_out_name (str): Name to give to gear output interfaces if none is specified. Default: ‘dout’

• gear/params:

• gear/params/extra (dict): Specifies additional keyword parameters and their defaults that can be specified for the gear instance besides the ones specified in the gear function signature. These parameters represent meta information available for the gear, which is interpreted by different PyGears subsystems. Default:

{
'sim_cls': None,   # Specify special class to be used to simulate the gear
'sim_setup': None, # Custom simulation setup function
'__base__': None,  # Used for polymorphism and @alternative decorator
'outnames': [],    # List of names to give to the output intefaces of a gear
'intfs': [],       # List of interfaces to connect outputs to
'name': None       # Gear instance name
}

• gear/params/meta (dict): Specifies additional parameters and their defaults that cannot be set on gear instantiation. These parameters represent meta information available for the gear, which is interpreted by different PyGears subsystems. Default:

{
'enablement': True # Used for polymorphism and @alternative decorator
}

• logger: Various PyGears subsystem loggers.

• logger/svgen: Logger for the SystemVerilog generation subsystem.

• logger/svgen/level (int): All messages that are logged with a verbosity level below this configured level value will be discarded. See Logging Levels for a list of levels.

• logger/svgen/warning: Configuration for logging at WARNING level

• logger/svgen/warning/exception (bool): If set to True, an exception will be raised whenever logging the message at WARNING level

• logger/svgen/warning/debug (bool): If set to True, whenever logging the message at WARNING level the debugger will be started and execution paused

• logger/svgen/error: Configuration for logging at ERROR level.

• logger/svgen/error/exception (bool): If set to True, an exception will be raised whenever logging the message at ERROR level

• logger/svgen/error/debug (bool): If set to True, whenever logging the message at ERROR level the debugger will be started and execution paused

• logger/svgen/print_traceback (bool): If set to True, the traceback will be printed along with the log message.

• logger/sim: Logger for the PyGears simulator. Structure is analog to logger/svgen.

• logger/conf: Logger for the PyGears infrastructure subsystem. Structure is analog to logger/svgen.

• logger/gear: Logger for the gears instantiation subsystem. Structure is analog to logger/svgen.

• logger/util: Logger for the various PyGears utility functions. Structure is analog to logger/svgen.

• logger/typing: Logger for the PyGears typing subsystem. Structure is analog to logger/svgen.

• logger/core: Logger for the PyGears core. Structure is analog to logger/svgen.

• logger/stack_traceback_fn (path): If set with a valid path, the stack trace will be logged to the file specified by the path.

• trace:

• level (TraceLevel): If set to TraceLevel.user, PyGears internal function calls will be hidden when printing the stack trace and when debugging with PDB.