-------------------------------------------------------------------------------
-- Copyright (c) 2003 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       : sw_ctrl.vhd
-- Author     : Mentor Graphics
-- Created    : 2003-04-18
-- Last update: 2003-04-18
-------------------------------------------------------------------------------
-- Description: Switch controller with integer signal output
-------------------------------------------------------------------------------
-- Revisions  :
-- Date        Version     Author              Description
-- 2003-04-18  1.0         Mentor Graphics     Created    
-------------------------------------------------------------------------------
-- Notes:
-- 1. Input switch position and time data in vector format.
-- 2. Number of points in both vectors must be equal.
-- 3. Use to drive EduLib multi-pole, multi-throw switch models.
-- 4. Assign integer sw_pos values according to switch being used.
-------------------------------------------------------------------------------

library IEEE;
use IEEE.MATH_REAL.all;

-- The MGC_AMS library contains a "conversion" package that includes the
-- time_vector and integer_vector type definitions (currently pending IEEE
-- approval). The source file (mgc_ams_additions.vhd) is located in the
-- SystemVision install tree.
library MGC_AMS;
use MGC_AMS.conversion.all;

entity sw_ctrl is

  generic (
    sw_pos  : integer_vector := (1, 2, 1, 2);  --Sample position data format
    sw_time : time_vector    := (0 ms, 1 ms, 2 ms, 3 ms)  -- Sample time data format
    );

  port (
    signal output : out integer := 1);

end entity sw_ctrl;

-------------------------------------------------------------------------------
-- architecture definition
-------------------------------------------------------------------------------
architecture ideal of sw_ctrl is

  signal out_signal : integer := 1;     -- intermediate signal

begin
  -- process to schedule output values
  set_output : process is
    variable count : integer := 0;
  begin
    wait until domain = time_domain;
    while count < sw_time'right loop
      out_signal <= sw_pos(count);      -- set out_signal to current position 
      wait for (sw_time(count + 1) - sw_time(count));  -- wait for next change 
      count      := count + 1;
    end loop;
    out_signal <= sw_pos(sw_pos'right);  -- hold output at last value
    wait;                               -- forever
  end process set_output;

  output <= out_signal;

end architecture ideal;

-------------------------------------------------------------------------------
-- Copyright (c) 2003 Mentor Graphics Corporation
-------------------------------------------------------------------------------