# File lib/ruby-vpi/core/callback.rb, line 92
    def cbValueChange aOptions = {}, &aHandler
      raise ArgumentError unless block_given?

      aOptions[:time]  ||= S_vpi_time.new(:type => VpiSuppressTime)
      aOptions[:value] ||= S_vpi_value.new(:format => VpiSuppressVal)

      alarm = S_cb_data.new(
        :reason => CbValueChange,
        :obj    => self,
        :time   => aOptions[:time],
        :value  => aOptions[:value],
        :index  => 0
      )

      vpi_register_cb alarm, &aHandler
    end