src/dev/IntPin.py

# Copyright 2019 Google, Inc.
#
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from m5.params import Port, VectorPort

INT_SOURCE_ROLE = 'Int Source Pin'
INT_SINK_ROLE = 'Int Sink Pin'
Port.compat(INT_SOURCE_ROLE, INT_SINK_ROLE)

# A source pin generally represents a single pin which might connect to
# multiple sinks.
class IntSourcePin(VectorPort):
    def __init__(self, desc):
        super().__init__(INT_SOURCE_ROLE, desc, is_source=True)

# A vector of source pins which might represent a bank of physical pins. Unlike
# IntSourcePin, each source pin in VectorIntSourcePin can only connect to a
# single sink pin. VectorIntSourcePin has the same definition as IntSourcePin
# right now, but will likely be implemented differently in the future.
# VectorIntSourcePin is defined as its own separate type to differentiate it
# from IntSourcePin and make it clear to the user how it should be interpreted
# and used.
class VectorIntSourcePin(VectorPort):
    def __init__(self, desc):
        super().__init__(INT_SOURCE_ROLE, desc, is_source=True)

# Each "physical" pin can be driven by a single source pin since there are no
# provisions for resolving competing signals running to the same pin.
class IntSinkPin(Port):
    def __init__(self, desc):
        super().__init__(INT_SINK_ROLE, desc)

# A vector of sink pins represents a bank of physical pins. For instance, an
# interrupt controller with many numbered input interrupts could represent them
# as a VectorIntSinkPin.
class VectorIntSinkPin(VectorPort):
    def __init__(self, desc):
        super().__init__(INT_SINK_ROLE, desc)