-- MIPS I system
-- Copyright 2011-2012 Stefan Schuermans <stefan@blinkenarea.org>
-- Copyleft GNU public license V2 or later
--          http://www.gnu.org/copyleft/gpl.html

LIBRARY ieee;
USE ieee.std_logic_1164.all;
USE ieee.numeric_std.all;

PACKAGE io_switches_pins IS

    TYPE t_io_switches_pins IS
        RECORD
            sw:     std_logic_vector(3 DOWNTO 0);
            east:   std_logic;
            north:  std_logic;
            south:  std_logic;
            west:   std_logic;
            center: std_logic;
            rot_a:  std_logic;
            rot_b:  std_logic;
        END RECORD;

    CONSTANT c_io_switches_pins_default: t_io_switches_pins := (
            sw     => "0000",
            east   => '0',
            north  => '0',
            south  => '0',
            west   => '0',
            center => '0',
            rot_a  => '1',
            rot_b  => '1'
        );

    FUNCTION io_switches_to_slv(switches: t_io_switches_pins)
        RETURN std_logic_vector;

    FUNCTION io_switches_from_slv(slv: std_logic_vector(31 DOWNTO 0))
        RETURN t_io_switches_pins;

END PACKAGE io_switches_pins;

PACKAGE BODY io_switches_pins IS

    FUNCTION io_switches_to_slv(switches: t_io_switches_pins)
        RETURN std_logic_vector IS
        VARIABLE v_slv: std_logic_vector(31 DOWNTO 0);
    BEGIN
        v_slv( 3 DOWNTO  0) := switches.sw;
        v_slv( 7 DOWNTO  4) := (OTHERS => '0');
        v_slv( 8)           := switches.east;
        v_slv( 9)           := switches.north;
        v_slv(10)           := switches.south;
        v_slv(11)           := switches.west;
        v_slv(15 DOWNTO 12) := (OTHERS => '0');
        v_slv(16)           := switches.center;
        v_slv(23 DOWNTO 17) := (OTHERS => '0');
        v_slv(24)           := switches.rot_a;
        v_slv(25)           := switches.rot_b;
        v_slv(31 DOWNTO 26) := (OTHERS => '0');
        RETURN v_slv;
    END FUNCTION io_switches_to_slv;

    FUNCTION io_switches_from_slv(slv: std_logic_vector(31 DOWNTO 0))
        RETURN t_io_switches_pins IS
        VARIABLE v_switches: t_io_switches_pins;
    BEGIN
        v_switches.sw     := slv( 3 DOWNTO  0);
        v_switches.east   := slv( 8);
        v_switches.north  := slv( 9);
        v_switches.south  := slv(10);
        v_switches.west   := slv(11);
        v_switches.center := slv(16);
        v_switches.rot_a  := slv(24);
        v_switches.rot_b  := slv(25);
        RETURN v_switches;
    END FUNCTION io_switches_from_slv;

END PACKAGE BODY io_switches_pins;