| Line 1... |
Line 1... |
-------------------------------------------------------------------------------
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-------------------------------------------------------------------------------
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--
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--
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-- The Clock Control unit.
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-- The Clock Control unit.
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-- Clock States and Machine Cycles are generated here.
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-- Clock States and Machine Cycles are generated here.
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--
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--
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-- $Id: clock_ctrl.vhd,v 1.3 2004-04-18 18:56:23 arniml Exp $
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-- $Id: clock_ctrl.vhd,v 1.4 2004-04-24 23:44:25 arniml Exp $
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--
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--
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-- Copyright (c) 2004, Arnim Laeuger (arniml@opencores.org)
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-- Copyright (c) 2004, Arnim Laeuger (arniml@opencores.org)
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--
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--
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-- All rights reserved
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-- All rights reserved
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--
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--
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| Line 78... |
Line 78... |
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end clock_ctrl;
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end clock_ctrl;
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|
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|
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library ieee;
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library ieee;
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use ieee.std_logic_arith.all;
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use ieee.numeric_std.all;
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|
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architecture rtl of clock_ctrl is
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architecture rtl of clock_ctrl is
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|
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-- The three XTAL1 cycles.
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-- The three XTAL1 cycles.
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signal xtal_q : unsigned(1 downto 0);
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signal xtal_q : unsigned(1 downto 0);
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| Line 129... |
Line 129... |
-----------------------------------------------------------------------------
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-----------------------------------------------------------------------------
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use_xtal_div: if xtal_div_3_g = 1 generate
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use_xtal_div: if xtal_div_3_g = 1 generate
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xtal: process (res_i, xtal_i)
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xtal: process (res_i, xtal_i)
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begin
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begin
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if res_i = res_active_c then
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if res_i = res_active_c then
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xtal_q <= CONV_UNSIGNED(0, 2);
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xtal_q <= TO_UNSIGNED(0, 2);
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|
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elsif xtal_i'event and xtal_i = clk_active_c then
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elsif xtal_i'event and xtal_i = clk_active_c then
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if xtal_q < 2 then
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if xtal_q < 2 then
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xtal_q <= xtal_q + 1;
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xtal_q <= xtal_q + 1;
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else
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else
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xtal_q <= CONV_UNSIGNED(0, 2);
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xtal_q <= TO_UNSIGNED(0, 2);
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end if;
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end if;
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|
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end if;
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end if;
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|
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end process xtal;
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end process xtal;
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| Line 158... |
Line 158... |
|
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-----------------------------------------------------------------------------
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-----------------------------------------------------------------------------
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-- XTAL1 is used directly for Clock States.
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-- XTAL1 is used directly for Clock States.
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-----------------------------------------------------------------------------
|
-----------------------------------------------------------------------------
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no_xtal_div: if xtal_div_3_g = 0 generate
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no_xtal_div: if xtal_div_3_g = 0 generate
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xtal_q <= CONV_UNSIGNED(0, 2);
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xtal_q <= TO_UNSIGNED(0, 2);
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|
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x1_s <= '1';
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x1_s <= '1';
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x2_s <= '1';
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x2_s <= '1';
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x3_s <= '1';
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x3_s <= '1';
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|
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| Line 378... |
Line 378... |
|
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-------------------------------------------------------------------------------
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-------------------------------------------------------------------------------
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-- File History:
|
-- File History:
|
--
|
--
|
-- $Log: not supported by cvs2svn $
|
-- $Log: not supported by cvs2svn $
|
|
-- Revision 1.3 2004/04/18 18:56:23 arniml
|
|
-- reset machine state to MSTATE3 to allow proper instruction fetch
|
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-- after reset
|
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--
|
-- Revision 1.2 2004/03/28 12:55:06 arniml
|
-- Revision 1.2 2004/03/28 12:55:06 arniml
|
-- move code for PROG out of if-branch for xtal3_s
|
-- move code for PROG out of if-branch for xtal3_s
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--
|
--
|
-- Revision 1.1 2004/03/23 21:31:52 arniml
|
-- Revision 1.1 2004/03/23 21:31:52 arniml
|
-- initial check-in
|
-- initial check-in
|
