Contents

# Value change / edge detection for handles.
#--
# Copyright 2007 Suraj N. Kurapati
# See the file named LICENSE for details.

require File.join(File.dirname(__FILE__), 'edge-methods.rb')

module RubyVPI
  class EdgeClass #:nodoc:
    require 'singleton'
    include Singleton

    def initialize
      @handles = []
      @lock = Mutex.new
    end

    # Begins monitoring the given handle for value change.
    def monitor aHandle
      # ignore handles that cannot hold a meaningful value
      type = VPI::vpi_get_str(VpiType, aHandle)
      return if type =~ /Bit|Array|Module|Parameter/

      @lock.synchronize do
        unless @handles.include? aHandle
          @handles << aHandle
          refresh_handle aHandle
        end
      end
    end

    # Refreshes the cached value of all monitored handles.
    def refresh_cache
      @lock.synchronize do
        @handles.each do |h|
          refresh_handle h
        end
      end
    end

    # Remember the current value as the "previous" value.
    def refresh_handle aHandle
      aHandle.instance_eval do
        @__edge__prev_val = get_value(VpiScalarVal)
      end
    end
  end

  Edge = EdgeClass.instance
end



module VPI
  class Handle
    RubyVPI::EdgeClass::DETECTION_METHODS.each {|m| class_eval m.body}

    alias posedge? change_01?
    alias negedge? change_10?

    # Tests if either a positive or negative edge has occurred.
    def edge?
      posedge? or negedge?
    end

    # Tests if the logic value of this handle has
    # changed since the last simulation time step.
    def change?
      old = @__edge__prev_val
      new = get_value(VpiScalarVal)

      old != new
    end
  end

  %w[
    vpi_handle_by_name
    vpi_handle_by_index
    vpi_handle
    vpi_scan
  ].each do |src|
    dst = "__value_change__#{src}"
    alias_method dst, src

    define_method src do |*args|
      if result = __send__(dst, *args)
        RubyVPI::Edge.monitor(result)
      end

      result
    end
  end
end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
ruby-vpi-20.0.0	lib/ruby-vpi/core/edge.rb
ruby-vpi-21.1.0	lib/ruby-vpi/core/edge.rb
ruby-vpi-21.0.0	lib/ruby-vpi/core/edge.rb