91 lines
2.0 KiB
Ruby
91 lines
2.0 KiB
Ruby
## Represents an IO port of a device
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class Port
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include Comparable
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# @!attribute [r] val
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# @return [Integer] the current value of the port
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attr_reader :val
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# @!attribute [r] width
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# @return [Integer] the width of the port
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attr_reader :width
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# Returns a new instance of Port
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# @overload set(width)
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# @param width [Integer] The width of the port
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# @overload set(width, name)
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# @param width [Integer] The width of the port
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# @param name [String] The name of the port
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def initialize(width, name="")
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@connected=[]
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@propagating=false
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@val=0
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@width=width
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@maxval = (2**@width)-1
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@strname=name
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end
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# Sets the port's value
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# @param val [Integer] The new value for the port
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# @return [void]
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def setval(val)
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# Prevent infinite loops when the connected port calls back when propagating.
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if !@propagating
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if val<=@maxval
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@val=val
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else
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raise ArgumentError,"#{val} is over maximum of #{@maxval}"
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end
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@propagating=true
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propagate()
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@propagating=false
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end
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end
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# Connects this port to another port
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# @param port [Port] The port to connect to
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# @return [void]
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def connect(port)
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@connected.push port
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port.connect_back(self)
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end
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# Returns a string representation for debugging
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# @return [String] String name of the port, or super if none
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def to_s()
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return super if @strname==""
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return @strname
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end
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# Method for Comparable module to use for comparasions.
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# @param obj [Object] Object to compare to
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# @return [void]
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def <=>(obj)
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if obj.class==Port
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return @val<=>obj.val
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elsif obj.is_a? Integer
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return @val<=>obj
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end
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end
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# Used by connect when setting up bidirectional connection.
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# @api private
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# @param (see #connect)
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# @return [void]
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def connect_back(port)
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@connected.push port
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end
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private
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# Propagates the value to all connected ports
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# @return [void]
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def propagate()
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@connected.each do |port|
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port.setval(@val)
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end
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end
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end
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