xhdl_std_ulogic.vhdl

VHDL和Verilog转换软件

   FUNCTION "SLL" (
      l        : std_ulogic_vector;
      r        : integer) RETURN std_ulogic_vector IS
   BEGIN
      RETURN(ShiftLeft(l, r));
   END "SLL";
   
   FUNCTION ShiftLeft (
      val      : std_ulogic_vector;
      shft     : integer) RETURN std_ulogic_vector IS
      
      VARIABLE int      : std_ulogic_vector(val'LENGTH+shft-1 DOWNTO 0);
      VARIABLE rtn      : std_ulogic_vector(val'RANGE);
      VARIABLE fill     : std_ulogic_vector(shft-1 DOWNTO 0) := (others => '0');
   BEGIN
      int := val & fill;
      rtn := int(val'LENGTH-1 DOWNTO 0);
      RETURN(rtn);
   END ShiftLeft;            
   
   FUNCTION "+" (
      l        : std_ulogic;
      r        : std_ulogic) RETURN std_ulogic_vector IS
      
      VARIABLE rtn      : std_ulogic_vector(1 downto 0);
      VARIABLE tmp      : std_ulogic_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";
         WHEN OTHERS => rtn := "XX";
      END CASE;
      RETURN(rtn);
   END "+";
      
   --   

   FUNCTION or_br (
      val : std_ulogic_vector) RETURN std_ulogic IS

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

   --
   
   FUNCTION and_br (
      val : std_ulogic_vector) RETURN std_ulogic IS

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

   --
   
   FUNCTION xor_br (
      val : std_ulogic_vector) RETURN std_ulogic IS

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

   --
   
   FUNCTION xnor_br (
      val : std_ulogic_vector) RETURN std_ulogic IS

      VARIABLE rtn : std_ulogic := '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 : std_ulogic_vector) RETURN std_ulogic IS

      VARIABLE rtn : std_ulogic := '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 : std_ulogic_vector) RETURN std_ulogic IS

      VARIABLE rtn : std_ulogic := '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 : std_ulogic_vector;
      op2 : std_ulogic_vector) RETURN std_ulogic_vector IS

      VARIABLE rtn      : std_ulogic_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 : std_ulogic;
      op2 : std_ulogic) RETURN std_ulogic IS

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

   --

   FUNCTION to_time (
      val : std_ulogic_vector) RETURN time IS
   
      VARIABLE rtn : time;
   BEGIN
      rtn := to_integer(val) * 1 ns;
      RETURN(rtn);
   END to_time;
   
   --

   FUNCTION to_string (
      val : std_ulogic_vector) RETURN string IS

      VARIABLE rtn   : string(1 TO val'LENGTH);
      ALIAS normal    : std_ulogic_vector(1 to val'LENGTH) IS val;
   BEGIN
       FOR index IN normal'RANGE LOOP
        CASE normal(index) IS
           WHEN '0' => rtn(index) := '0';
            WHEN 'L' => rtn(index) := 'L';
            WHEN '1' => rtn(index) := '1';
            WHEN 'H' => rtn(index) := 'H';
            WHEN 'U' => rtn(index) := 'U';
            WHEN 'Z' => rtn(index) := 'Z';
            WHEN 'W' => rtn(index) := 'W';
            WHEN OTHERS => rtn(index) := 'X';
         END CASE;
      END LOOP;
      RETURN rtn;
   END to_string;

    --
    
   FUNCTION to_string (
      val : std_ulogic) RETURN character IS

      VARIABLE rtn      : character;
   BEGIN
     CASE val IS
         WHEN '0' => rtn := '0';
         WHEN 'L' => rtn := 'L';
         WHEN '1' => rtn := '1';
         WHEN 'H' => rtn := 'H';
         WHEN 'U' => rtn := 'U';
         WHEN 'Z' => rtn := 'Z';
         WHEN 'W' => rtn := 'W';
         WHEN OTHERS => rtn := 'X';
      END CASE;
      RETURN rtn;
     END to_string;
   
  FUNCTION to_octstring (
      val      : IN std_ulogic_vector) RETURN string IS
   
      constant extra : integer := val'length rem 3;
      constant len    : integer := ((val'length-1)/3)+1;
      variable rtn  : string(1 to len);
      variable vec   : std_ulogic_vector((extra + val'length-1) downto 0);
      
   BEGIN
      case extra is
         when 0      => vec := val;
         when 1      => vec := '0' & val;
         when 2      => vec := "00" & val;
         when others => vec := val;
      end case;
      for x in len downto 1 loop
         case vec(2 downto 0) is
            when "000"     => rtn(x) := '0';
            when "001"     => rtn(x) := '1';
            when "010"     => rtn(x) := '2';
            when "011"     => rtn(x) := '3';
            when "100"     => rtn(x) := '4';
            when "101"     => rtn(x) := '5';
            when "110"     => rtn(x) := '6';
            when "111"     => rtn(x) := '7';
            when "UUU"     => rtn(x) := 'U';
            when "ZZZ"     => rtn(x) := 'Z';
            when "XXX"     => rtn(x) := 'X';
            when others      => rtn(x) := '?';
         end case;
         vec := "000" & vec(val'length-1 downto 3);
      end loop;
      return(rtn);
   END to_octstring;
  
  FUNCTION to_decstring (
      val      : IN std_ulogic_vector) RETURN string IS
   
      variable int   : integer;
   BEGIN
      int := to_integer(val);
      return(to_string(val));
   END to_decstring;
    
  FUNCTION to_hexstring (
      val      : IN std_ulogic_vector) RETURN string IS
   
      constant extra : integer := val'length rem 4;
      constant len    : integer := ((val'length-1)/4)+1;
      variable rtn  : string(1 to len);
      variable vec   : std_ulogic_vector((extra + val'length-1) downto 0);
      
   BEGIN
      case extra is
         when 0      => vec := val;
         when 1      => vec := '0' & val;
         when 2      => vec := "00" & val;
         when 3      => vec := "000" & val;
         when others => vec := val;
      end case;
      for x in len downto 1 loop
         case vec(3 downto 0) is
            when "0000"    => rtn(x) := '0';
            when "0001"     => rtn(x) := '1';
            when "0010"      => rtn(x) := '2';
            when "0011"    => rtn(x) := '3';
            when "0100"     => rtn(x) := '4';
            when "0101"      => rtn(x) := '5';
            when "0110"    => rtn(x) := '6';
            when "0111"     => rtn(x) := '7';
            when "1000"      => rtn(x) := '8';
            when "1001"    => rtn(x) := '9';
            when "1010"     => rtn(x) := 'A';
            when "1011"      => rtn(x) := 'B';
            when "1100"    => rtn(x) := 'C';
            when "1101"     => rtn(x) := 'D';
            when "1110"      => rtn(x) := 'E';
            when "1111"    => rtn(x) := 'F';
            when "UUUU"     => rtn(x) := 'U';
            when "ZZZZ"      => rtn(x) := 'Z';
            when "XXXX"    => rtn(x) := 'X';
            when others     => rtn(x) := '?';
         end case;
         vec := "0000" & vec(val'length-1 downto 4);
      end loop;
      return(rtn);
   END to_hexstring;
   
END;