xhdl_bit.vhdl

VHDL和Verilog转换软件

--
-- Copyright Notice and Proprietary Information
--
-- Copyright (C) 1997-2002 X-Tek Corporation. All rights reserved. This Software 
-- and documentation are owned by X-Tek Corporation, and may be used only as 
-- authorized in the license agreement controlling such use. No part of this 
-- publication may be reproduced, transmitted, or translated, in any form or by 
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-- agreement.
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-- Disclaimer
--
-- X-Tek Corporation makes no warranty of any kind, express or implied, with regard 
-- to this material, including, but not limited to, the implied warranties of 
-- merchantability and fitness for a particular purpose.
--
-- X-Tek Corporation reserves the right to make changes without further notice to 
-- the products described herein. X-Tek Corporation does not assume any liability 
-- arising out of the application or use of any product or circuit described 
-- herein. The X-Tek products described herein are not authorized for use as 
-- components in life-support devices.
--
--
-- Rev 2001.0226
--
-- Rev 2001.0324
--    a) Added function    
--          FUNCTION conv_bit_vector (
--             val      : IN boolean;
--             len      : IN integer) RETURN bit_vector;
--
-- Rev 2002.0521
--    a) Removed non-synthesizable functions to_time and to_*string
--

LIBRARY ieee;
USE ieee.std_logic_1164.all;
LIBRARY std;
USE std.textio.all;

PACKAGE xhdl_bit IS

   FUNCTION conv_bit (
      val      : IN boolean) RETURN bit;
      
   FUNCTION conv_bit_vector (
      val      : IN boolean;
      len      : IN integer) RETURN bit_vector;
     
   FUNCTION conv_bit_vector (
      val      : IN integer;
      len      : IN integer) RETURN bit_vector;
     
   FUNCTION to_bit (
      val      : IN boolean) RETURN bit;
      
   FUNCTION to_bitvector (
      val      : IN integer;
      len      : IN integer) RETURN bit_vector;
      
   FUNCTION to_bitvector (
      val      : IN boolean;
      len      : IN integer) RETURN bit_vector;
      
   FUNCTION to_integer (
      val      : bit) RETURN integer;
   
   FUNCTION to_integer (
      val      : bit_vector) RETURN integer;
   
   FUNCTION "SRL" (
      l        : bit_vector;
      r        : integer) RETURN bit_vector;
   
   FUNCTION ShiftRight (
      val      : bit_vector;
      shft     : integer) RETURN bit_vector;
   
   FUNCTION "SLL" (
      l        : bit_vector;
      r        : integer) RETURN bit_vector;
   
   FUNCTION ShiftLeft (
      val      : bit_vector;
      shft     : integer) RETURN bit_vector;
   
   FUNCTION "+" (
      l        : bit;
      r        : bit) RETURN bit_vector;
   
   FUNCTION or_br (
      val : bit_vector) RETURN bit;
   
   FUNCTION and_br (
      val : bit_vector) RETURN bit;

   FUNCTION xor_br (
      val : bit_vector) RETURN bit;

   FUNCTION xnor_br (
      val : bit_vector) RETURN bit;

   FUNCTION nor_br (
      val : bit_vector) RETURN bit;

   FUNCTION nand_br (
      val : bit_vector) RETURN bit;

   FUNCTION select_expr (
      sel : boolean;
      op1 : bit_vector;
      op2 : bit_vector) RETURN bit_vector;

   FUNCTION select_expr (
      sel : boolean;
      op1 : bit;
      op2 : bit) RETURN bit;

END;

PACKAGE BODY xhdl_bit IS

   FUNCTION conv_bit (
      val      : IN boolean) RETURN bit IS
   BEGIN
      RETURN(to_bit(val));
   END conv_bit;

   FUNCTION to_bit (
      val      : IN boolean) RETURN bit IS
   BEGIN
      IF (val) THEN
         RETURN('1');
      ELSE
         RETURN('0');
      END IF;
   END to_bit;
   
   FUNCTION conv_bit_vector (
      val      : IN boolean;
      len      : IN integer) RETURN bit_vector IS
      
      VARIABLE rtn      : bit_vector(len-1 DOWNTO 0) := (OTHERS => '0');
      VARIABLE b        : bit;
   BEGIN
      IF (val) THEN
         b := '1';
      ELSE
         b := '0';
      END IF;
      FOR index IN 0 TO len-1 LOOP
         rtn(index) := b;
      END LOOP;
	   RETURN(rtn);
	END conv_bit_vector;

   FUNCTION conv_bit_vector (
      val      : IN integer;
      len      : IN integer) RETURN bit_vector IS
   BEGIN
	   RETURN(to_bitvector(val, len));
	END conv_bit_vector;
 
   --
   
   FUNCTION to_bitvector (
      val      : IN integer;
      len      : IN integer) RETURN bit_vector IS
      
      VARIABLE rtn      : bit_vector(len-1 DOWNTO 0) := (OTHERS => '0');
      VARIABLE num  : integer := val;
      VARIABLE r       : integer;
   BEGIN
      FOR index IN 0 TO len-1 LOOP
         r := num rem 2;
         num := num/2;
         IF (r = 1) THEN
            rtn(index) := '1';
         ELSE
            rtn(index) := '0';
         END IF;
      END LOOP;
      RETURN(rtn);
   END to_bitvector;
   
   --   
      
   FUNCTION to_bitvector (
      val      : IN boolean;
      len      : IN integer) RETURN bit_vector IS
      
      VARIABLE rtn      : bit_vector(len-1 DOWNTO 0) := (OTHERS => '0');
   BEGIN
      rtn(0) := to_bit(val);
      RETURN(rtn);
   END to_bitvector;
         
   --   
      
  FUNCTION to_integer (
      val      : bit) RETURN integer IS

      VARIABLE rtn      : integer := 0;
   BEGIN
      IF (val = '1') THEN
         rtn := 1;
      ELSE
         rtn := 0;
      END IF;
      RETURN(rtn);
   END to_integer;
                  
   --
      
   FUNCTION to_integer (
      val      : bit_vector) RETURN integer IS
      
      CONSTANT vec      : bit_vector(val'high-val'low DOWNTO 0) := val;      
      VARIABLE rtn      : integer := 0;
   BEGIN
      FOR index IN vec'RANGE LOOP
         IF (vec(index) = '1') THEN
            rtn := rtn + (2**index);
         END IF;
      END LOOP;
      RETURN(rtn);
   END to_integer;
         
   --
   FUNCTION "SRL" (
      l        : bit_vector;
      r        : integer) RETURN bit_vector IS
   BEGIN
      RETURN(ShiftRight(l, r));
   END "SRL";
   
   FUNCTION ShiftRight (
      val      : bit_vector;
      shft     : integer) RETURN bit_vector IS
      
      VARIABLE int      : bit_vector(val'LENGTH+shft-1 DOWNTO 0);
      VARIABLE rtn      : bit_vector(val'RANGE);
      VARIABLE fill     : bit_vector(shft-1 DOWNTO 0) := (others => '0');
   BEGIN
      int := fill & val;
      rtn := int(val'LENGTH+shft-1 DOWNTO shft);
      RETURN(rtn);
   END ShiftRight;            
   
   --

   FUNCTION "SLL" (
      l        : bit_vector;
      r        : integer) RETURN bit_vector IS
   BEGIN
      RETURN(ShiftLeft(l, r));
   END "SLL";
   
   FUNCTION ShiftLeft (
      val      : bit_vector;
      shft     : integer) RETURN bit_vector IS
      
      VARIABLE int      : bit_vector(val'LENGTH+shft-1 DOWNTO 0);
      VARIABLE rtn      : bit_vector(val'RANGE);
      VARIABLE fill     : bit_vector(shft-1 DOWNTO 0) := (others => '0');
   BEGIN
      int := val & fill;
      rtn := int(val'LENGTH-1 DOWNTO 0);
      RETURN(rtn);
   END ShiftLeft;            
   
   FUNCTION "+" (
      l        : bit;
      r        : bit) RETURN bit_vector IS
      
      VARIABLE rtn      : bit_vector(1 downto 0);
      VARIABLE tmp      : bit_vector(1 downto 0);
   BEGIN
      tmp := l & r;
      CASE tmp IS
         WHEN "00" => rtn := "00";
         WHEN "01" => rtn := "01";
         WHEN "10" => rtn := "01";
         WHEN "11" => rtn := "10";
      END CASE;
      RETURN(rtn);
   END "+";
      
   --   

   FUNCTION or_br (
      val : bit_vector) RETURN bit IS
   
      VARIABLE rtn : bit := '0';
   BEGIN
      FOR index IN val'RANGE LOOP
         rtn := rtn OR val(index);
      END LOOP;
      RETURN(rtn);
   END or_br;

   --
   
   FUNCTION and_br (
      val : bit_vector) RETURN bit IS

      VARIABLE rtn : bit := '1';
   BEGIN
      FOR index IN val'RANGE LOOP
         rtn := rtn AND val(index);
      END LOOP;
      RETURN(rtn);
   END and_br;

   --
   
   FUNCTION xor_br (
      val : bit_vector) RETURN bit IS

      VARIABLE rtn : bit := '0';
   BEGIN
      FOR index IN val'RANGE LOOP
         rtn := rtn XOR val(index);
      END LOOP;
      RETURN(rtn);
   END xor_br;

   --
   
   FUNCTION xnor_br (
      val : bit_vector) RETURN bit IS

      VARIABLE rtn : bit := '0';
   BEGIN
      FOR index IN val'RANGE LOOP
         rtn := rtn XOR val(index);
      END LOOP;
      RETURN(NOT rtn);
   END xnor_br;

   --

   FUNCTION nor_br (
      val : bit_vector) RETURN bit IS

      VARIABLE rtn : bit := '0';
   BEGIN
      FOR index IN val'RANGE LOOP
         rtn := rtn OR val(index);
      END LOOP;
      RETURN(NOT rtn);
   END nor_br;
   
   --

   FUNCTION nand_br (
      val : bit_vector) RETURN bit IS

      VARIABLE rtn : bit := '0';
   BEGIN
      FOR index IN val'RANGE LOOP
         rtn := rtn AND val(index);
      END LOOP;
      RETURN(NOT rtn);
   END nand_br;

   --

   FUNCTION select_expr (
      sel : boolean;
      op1 : bit_vector;
      op2 : bit_vector) RETURN bit_vector IS

      VARIABLE rtn      : bit_vector(op1'RANGE);
   BEGIN
      IF(sel) THEN
         rtn := op1;
      ELSE
         rtn := op2;
      END IF;
      
      RETURN (rtn);
   END select_expr;
   
   --

   FUNCTION select_expr (
      sel : boolean;
      op1 : bit;
      op2 : bit) RETURN bit IS

      VARIABLE rtn      : bit;
   BEGIN
      IF(sel) THEN
         rtn := op1;
      ELSE
         rtn := op2;
      END IF;
      
      RETURN (rtn);
   END select_expr;
   
END;