-------------------------------------------------------------------------------
-- Copyright (c) 2001 Mentor Graphics Corporation
--
-- This model is a component of the Mentor Graphics VHDL-AMS educational open 
-- source model library, and is covered by this license agreement. This model,
-- including any updates, modifications, revisions, copies, and documentation 
-- are copyrighted works of Mentor Graphics. USE OF THIS MODEL INDICATES YOUR 
-- COMPLETE AND UNCONDITIONAL ACCEPTANCE OF THE TERMS AND CONDITIONS SET FORTH
-- IN THIS LICENSE AGREEMENT.  Mentor Graphics grants you a non-exclusive 
-- license to use, reproduce, modify and distribute this model, provided that:
-- (a) no fee or other consideration is charged for any distribution except 
-- compilations distributed in accordance with Section (d) of this license 
-- agreement; (b) the comment text embedded in this model is included verbatim
-- in each copy of this model made or distributed by you, whether or not such 
-- version is modified; (c) any modified version must include a conspicuous 
-- notice that this model has been modified and the date of modification; and 
-- (d) any compilations sold by you that include this model must include a 
-- conspicuous notice that this model is available from Mentor Graphics in its
-- original form at no charge.
--
-- THIS MODEL IS LICENSED TO YOU "AS IS" AND WITH NO WARRANTIES, EXPRESS OR 
-- IMPLIED.  MENTOR GRAPHICS SPECIFICALLY DISCLAIMS ALL IMPLIED WARRANTIES OF 
-- MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  MENTOR GRAPHICS SHALL
-- HAVE NO RESPONSIBILITY FOR ANY DAMAGES WHATSOEVER.
-------------------------------------------------------------------------------
-- File       : i_pulse.vhd
-- Author     : Mentor Graphics
-- Created    : 2001/06/16
-- Last update: 2003-05-13
-------------------------------------------------------------------------------
-- Description: Electrical Current Pulse Source
--              Includes Frequency Domain Settings
-------------------------------------------------------------------------------
-- Revisions  :
-- Date        Version     Author              Description
-- 2001/06/16  1.0         Mentor Graphics     Created
-- 2001/07/09  1.1         Mentor Graphics     Changed input parameters to type
--                                             time.  Uses time2real function.
--                                             Pulsewidth no longer includes
--                                             rise and fall times.
-- 2002-06-06  1.2         Mentor Graphics     Fixed bug when delay=0
-------------------------------------------------------------------------------

library IEEE;
use IEEE.math_real.all;
-- Use IEEE natures and packages
use IEEE.electrical_systems.all;

entity i_pulse is

  generic (
    initial  : current := 0.0;          -- initial value [Amps]
    pulse    : current;                 -- pulsed value [Amps]
    ti2p     : time := 1ns;             -- initial to pulse [Sec]
    tp2i     : time := 1ns;             -- pulse to initial [Sec]
    delay    : time := 0ms;             -- delay time [Sec]
    width    : time;                    -- duration of pulse [Sec]
    period   : time;                    -- period [Sec]
    ac_mag   : current := 1.0;          -- AC magnitude [Amps]
    ac_phase : real    := 0.0);         -- AC phase [Degrees]

  port (
    terminal pos, neg : electrical);

end entity i_pulse;

-------------------------------------------------------------------------------
-- Ideal Architecture
-------------------------------------------------------------------------------
architecture ideal of i_pulse is

-- Declare Through and Across Branch Quantities  
  quantity v across i through pos to neg;
-- Declare quantity in frequency domain for AC analysis 
  quantity ac_spec : real spectrum ac_mag, math_2_pi*ac_phase/360.0;
-- Signal used in CreateEvent Process below
  signal   pulse_signal : current := initial;

-- Convert ti2p and tp2i generics to type REAL (needed for 'RAMP attribute)
-- Note: these lines gave an error during simulation.  Had to use a
-- function call instead.
--  constant ri2p : real := time'pos(ti2p) * 1.0e-15;
--  constant rp2i : real := time'pos(tp2i) * 1.0e-15;
  
-- Function to convert numbers of type TIME to type REAL
  function time2real(tt : time) return real is
  begin
    return time'pos(tt) * 1.0e-15;
  end time2real;
-- Convert ti2p and tp2i generics to type REAL (needed for 'RAMP attribute)
  constant ri2p : real := time2real(ti2p);
  constant rp2i : real := time2real(tp2i);

begin

  if domain = quiescent_domain or domain = time_domain use
    i == pulse_signal'ramp(ri2p, rp2i); -- create rise and fall transitions
  else
    i   == ac_spec;     -- used for Frequency (AC) analysis
  end use;

  -- purpose: Create events to define pulse shape
  -- type   : combinational
  -- inputs : 
  -- outputs: pulse_signal
  CreateEvent : process
  begin
    wait until domain = time_domain;    -- Run process in Time Domain only
    wait for delay;
    loop
      pulse_signal <= pulse;
      wait for (width + ti2p);
      pulse_signal <= initial;
      wait for (period - width - ti2p);
    end loop;
  end process CreateEvent;

end architecture ideal;

-------------------------------------------------------------------------------
-- Copyright (c) 2001 Mentor Graphics Corporation
-------------------------------------------------------------------------------