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lustrec-tests / vhdl_json / vhdl_files / 2-exportOK / cnes_guidelines / rule / data / STD_05600_good.vhd @ 2051e520

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-- Company   : CNES
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-- Author    : Mickael Carl (CNES)
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-- Copyright : Copyright (c) CNES.
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-- Licensing : GNU GPLv3
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-- Version         : V1
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-- Version history :
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--    V1 : 2015-04-13 : Mickael Carl (CNES): Creation
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-- File name          : STD_05600_good.vhd
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-- File Creation date : 2015-04-13
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-- Project name       : VHDL Handbook CNES Edition
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-- Softwares             :  Microsoft Windows (Windows 7) - Editor (Eclipse + VEditor)
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-- Description : Handbook example: Unsuitability of combinational feedbacks: good example
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--
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-- Limitations : This file is an example of the VHDL handbook made by CNES. It is a stub aimed at
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--               demonstrating good practices in VHDL and as such, its design is minimalistic.
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--               It is provided as is, without any warranty.
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--               This example is compliant with the Handbook version 1.
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--
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-------------------------------------------------------------------------------------------------
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-- Naming conventions:
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--
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-- i_Port: Input entity port
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-- o_Port: Output entity port
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-- b_Port: Bidirectional entity port
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-- g_My_Generic: Generic entity port
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--
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-- c_My_Constant: Constant definition
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-- t_My_Type: Custom type definition
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--
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-- My_Signal_n: Active low signal
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-- v_My_Variable: Variable
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-- sm_My_Signal: FSM signal
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-- pkg_Param: Element Param coming from a package
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--
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-- My_Signal_re: Rising edge detection of My_Signal
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-- My_Signal_fe: Falling edge detection of My_Signal
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-- My_Signal_rX: X times registered My_Signal signal
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--
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-- P_Process_Name: Process
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--
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library IEEE;
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use IEEE.std_logic_1164.all;
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use IEEE.numeric_std.all;
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library work;
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use work.pkg_HBK.all;
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--CODE
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entity STD_05600_good is
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   port (
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      i_Clock   : in  std_logic;        -- Clock signal
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      i_Reset_n : in  std_logic;        -- Reset signal
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      i_A       : in  std_logic;        -- First Mux input
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      i_B       : in  std_logic;        -- Second Mux input
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      i_Sel     : in  std_logic;        -- Mux selector
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      o_O       : out std_logic         -- Mux output
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      );
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end STD_05600_good;
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architecture Behavioral of STD_05600_good is
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   signal Mux_Sel   : std_logic;        -- Combinational select
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   signal Mux_Sel_r : std_logic;        -- Synchronized select
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   signal O         : std_logic;        -- Module output
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begin
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   Mux_Sel <= i_Sel and O;
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   -- Synchronizes the Mux_Sel signal to avoid combinational feedback
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   DFF : DFlipFlop
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      port map (
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         i_Clock   => i_Clock,
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         i_Reset_n => i_Reset_n,
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         i_D       => Mux_Sel,
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         o_Q       => Mux_Sel_r
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         );
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   -- Combinational Mux selecting A or B depending on Mux_Sel_r value
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   Mux1 : Mux
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      port map (
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         i_A => i_A,
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         i_B => i_B,
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         i_S => Mux_Sel_r,
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         o_O => O
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         );
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   o_O <= O;
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end Behavioral;
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--CODE