jens
2f7ab91e0d
git-svn-id: http://moon:8086/svn/vhdl/trunk@1429 cc03376c-175c-47c8-b038-4cd826a8556b
44 lines
856 B
VHDL
44 lines
856 B
VHDL
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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package fifo_ctrl_pkg is
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-- Constants
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-- Types
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-- Functions
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function bin2gray(xb : unsigned) return unsigned;
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function gray2bin(xg : unsigned) return unsigned;
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end fifo_ctrl_pkg;
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package body fifo_ctrl_pkg is
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function bin2gray(xb : unsigned) return unsigned is
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variable xg : unsigned(xb'left downto xb'right);
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begin
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xg(xg'left) := xb(xb'left);
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for i in 1 to xb'left loop
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xg(xg'left-i) := xb(xb'left-i+1) xor xb(xb'left-i);
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end loop;
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return xg;
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end bin2gray;
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function gray2bin(xg : unsigned) return unsigned is
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variable xb : unsigned(xg'left downto xg'right);
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begin
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xb(xb'left) := xg(xg'left);
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for i in 1 to xg'left loop
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xb(xb'left-i) := xb(xb'left-i+1) xor xg(xg'left-i);
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end loop;
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return xb;
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end gray2bin;
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end fifo_ctrl_pkg;
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