txt_util.vhd

VHDL的字符串处理函数库

   function	to_upper(s:	string)	return string is

	 variable uppercase: string	(s'range);

   begin

	 for i in s'range loop
		uppercase(i):= to_upper(s(i));
	 end loop;
	 return	uppercase;

   end to_upper;



   -- convert a	string to lower	case

   function	to_lower(s:	string)	return string is

	 variable lowercase: string	(s'range);

   begin

	 for i in s'range loop
		lowercase(i):= to_lower(s(i));
	 end loop;
	 return	lowercase;

   end to_lower;



-- functions to	convert	strings	into other types


-- converts	a character	into a std_logic

function to_std_logic(c: character)	return std_logic is	
	variable sl: std_logic;
	begin
	  case c is
		when 'U' =>	
		   sl := 'U'; 
		when 'X' =>
		   sl := 'X';
		when '0' =>	
		   sl := '0';
		when '1' =>	
		   sl := '1';
		when 'Z' =>	
		   sl := 'Z';
		when 'W' =>	
		   sl := 'W';
		when 'L' =>	
		   sl := 'L';
		when 'H' =>	
		   sl := 'H';
		when '-' =>	
		   sl := '-';
		when others	=>
		   sl := 'X'; 
	end	case;
   return sl;
  end to_std_logic;


-- converts	a string into std_logic_vector

function to_std_logic_vector(s:	string)	return std_logic_vector	is 
  variable slv:	std_logic_vector(s'high-s'low downto 0);
  variable k: integer;
begin
   k :=	s'high-s'low;
  for i	in s'range loop
	 slv(k)	:= to_std_logic(s(i));
	 k		:= k - 1;
  end loop;
  return slv;
end	to_std_logic_vector;									   

-- converts	an integer to a	string
function int_to_str	(value : integer; len :	POSITIVE) return string	is
variable ivalue	: integer := 0;
variable index	: integer := 0;
variable digit : integer :=	0;
variable line_no: string(16	downto 1) := "                "; 
begin
	assert len <= 16
		report "ERROR : The length of the output string can not be great than 16 !"
		severity ERROR;

	if value > 0 THEN
		ivalue := value;
	elsif value	< 0	THEN
		ivalue := -	value;
	else
		ivalue := 0;
	end	if;
	index := 0;
	
	while (ivalue >	0) loop
		index := index + 1;
		digit := ivalue	MOD	10;
		ivalue := ivalue/10;
		case digit is
			when 0 => line_no(index) :=	'0';
			when 1 => line_no(index) :=	'1';
			when 2 => line_no(index) :=	'2';
			when 3 => line_no(index) :=	'3';
			when 4 => line_no(index) :=	'4';
			when 5 => line_no(index) :=	'5';
			when 6 => line_no(index) :=	'6';
			when 7 => line_no(index) :=	'7';
			when 8 => line_no(index) :=	'8';
			when 9 => line_no(index) :=	'9';
			when others	=>
				ASSERT FALSE
				REPORT "Illegal number!"
				SEVERITY ERROR;
		end	case;
	end	loop;

	if value = 0 THEN
		index := 1;
		line_no(index) := '0';
	elsif value	< 0	THEN
		index := index + 1;
		line_no(index) := '-';
	end	if;

	assert len >= index
		report "ERROR : The length of the output string is too small !"
		severity ERROR;

	return line_no(len downto 1);
end	int_to_str;

--	converts a string to an	integer
function str_to_int	( str :	string ) return	integer	is
variable len : integer := str'length;
variable ivalue	: integer := 0;
variable digit : integer :=	0;
variable isign : integer	:= 0;
begin
	for	i in str'RANGE loop
		case str(i)	is
			when '0' =>
				digit := 0;
				if isign=0 then
					isign := 1;
				end	if;
			when '1' =>
				digit := 1;
				if isign=0 then
					isign := 1;
				end	if;
			when '2' =>
				digit := 2;
				if isign=0 then
					isign := 1;
				end	if;
			when '3' =>
				digit := 3;
				if isign=0 then
					isign := 1;
				end	if;
			when '4' =>
				digit := 4;
				if isign=0 then
					isign := 1;
				end	if;
			when '5' =>
				digit := 5;
				if isign=0 then
					isign := 1;
				end	if;
			when '6' =>
				digit := 6;
				if isign=0 then
					isign := 1;
				end	if;
			when '7' =>
				digit := 7;
				if isign=0 then
					isign := 1;
				end	if;
			when '8' =>
				digit := 8;
				if isign=0 then
					isign := 1;
				end	if;
			when '9' =>
				digit := 9;
				if isign=0 then
					isign := 1;
				end	if;
			when ' ' | ',' =>
				next;
			when '+' =>
				if isign=0 then
					isign := 1;
				else
					ASSERT FALSE
					REPORT "ERROR : Illegal Character '" & str(i) & "' in string parameter ! "
					SEVERITY ERROR;
				end	if;
			when '-' =>
				if isign=0 then
					isign := -1;
				else
					ASSERT FALSE
					REPORT "ERROR : Illegal Character '" & str(i) & "' in string parameter ! "
					SEVERITY ERROR;
				end	if;
			when others	=>
				ASSERT FALSE
				REPORT "ERROR : Illegal Character '" & str(i) & "' in string parameter ! "
				SEVERITY ERROR;
		end	case;
		ivalue := ivalue * 10 +	digit;
	end	loop;

	if isign=0 then
		ASSERT FALSE
		REPORT "ERROR : The input string is not a number string ! "
		SEVERITY ERROR;
	END	IF;
	ivalue := ivalue * isign;

	return ivalue;
end	str_to_int;

-- converts	an integer to a	hexadecimal	number string
function int_to_hex_str	(value : integer; len :	POSITIVE) return string	is
variable ivalue	: integer := 0;
variable index	: integer := 0;
variable digit : integer :=	0;
variable line_no: string(16	downto 1) := "0000000000000000";
variable len_line	: integer;
begin
	assert len <= 16
		report "ERROR : The length of the output string can not be great than 16 ! "
		severity ERROR;

	assert value >= 0
		report "ERROR : The value input can not be negative ! "
		severity ERROR;

	ivalue := value;
	index := 0;
	
	while (ivalue >	0) loop
		index := index + 1;
		digit := ivalue	MOD	16;
		ivalue := ivalue/16;
		case digit is
			when 0	=> line_no(index) := '0';
			when 1	=> line_no(index) := '1';
			when 2	=> line_no(index) := '2';
			when 3	=> line_no(index) := '3';
			when 4	=> line_no(index) := '4';
			when 5	=> line_no(index) := '5';
			when 6	=> line_no(index) := '6';
			when 7	=> line_no(index) := '7';
			when 8	=> line_no(index) := '8';
			when 9	=> line_no(index) := '9';
			when 10	=> line_no(index) := 'A';
			when 11	=> line_no(index) := 'B';
			when 12	=> line_no(index) := 'C';
			when 13	=> line_no(index) := 'D';
			when 14	=> line_no(index) := 'E';
			when 15	=> line_no(index) := 'F';
			when others	=>
				ASSERT FALSE
				REPORT "Illegal number ! "
				SEVERITY ERROR;
		end	case;
	end	loop;

	if ivalue=0 then
		index := 1;
	end if;

	assert len >= index
		report "ERROR : The length of the output string is too small ! "
		severity ERROR;

	return line_no(len downto 1);
end	int_to_hex_str;

--	converts a hexadecimal number string to	a integer
function hex_str_to_int	(str : string) return integer is
variable len : integer := str'length;
variable ivalue	: integer := 0;
variable digit : integer :=	0;
begin
	for	i in str'RANGE loop
		case str(i)	is
			when '0' =>	digit := 0;
			when '1' =>	digit := 1;
			when '2' =>	digit := 2;
			when '3' =>	digit := 3;
			when '4' =>	digit := 4;
			when '5' =>	digit := 5;
			when '6' =>	digit := 6;
			when '7' =>	digit := 7;
			when '8' =>	digit := 8;
			when '9' =>	digit := 9;
			when 'A' =>	digit := 10;
			when 'a' =>	digit := 10;
			when 'B' =>	digit := 11;
			when 'b' =>	digit := 11;
			when 'C' =>	digit := 12;
			when 'c' =>	digit := 12;
			when 'D' =>	digit := 13;
			when 'd' =>	digit := 13;
			when 'E' =>	digit := 14;
			when 'e' =>	digit := 14;
			when 'F' =>	digit := 15;
			when 'f' =>	digit := 15;
			when ' ' | ',' =>
				next;
			when others	=>
				ASSERT FALSE
				REPORT "Illegal character '" & str(i) & "' in Intel Hex File ! "
				SEVERITY ERROR;
		end	case;
		ivalue := ivalue * 16 +	digit;
	end	loop;
	return ivalue;
end	hex_str_to_int;

									  
									   
									   
----------------
--	file I/O  --
----------------



-- read	variable length	string from	input file
	 
procedure str_read(file	in_file: TEXT; 
				   res_string: out string) is
	   
	   variable	l:		   line;
	   variable	c:		   character;
	   variable	is_string: boolean;
	   
   begin
		   
	 readline(in_file, l);
	 --	clear the contents of the result string
	 for i in res_string'range loop
		 res_string(i) := ' ';
	 end loop;	 
	 --	read all characters	of the line, up	to the length  
	 --	of the results string
	 for i in res_string'range loop
		read(l,	c, is_string);
		res_string(i) := c;
		if not is_string then -- found end of line
		   exit;
		end	if;	  
	 end loop; 
					 
end	str_read;


-- print string	to a file
procedure print(file out_file: TEXT;
				new_string:	in	string)	is
	   
	   variable	l: line;
	   
   begin
	  
	 write(l, new_string);
	 writeline(out_file, l);
					 
end	print;


-- print character to a	file and start new line
procedure print(file out_file: TEXT;
				char: in  character) is
	   
	   variable	l: line;
	   
   begin
	  
	 write(l, char);
	 writeline(out_file, l);
					 
end	print;



-- appends contents	of a string	to a file until	line feed occurs
-- (LF is considered to	be the end of the string)

procedure str_write(file out_file: TEXT; 
					new_string:	in	string)	is
 begin
	  
   for i in	new_string'range loop
	  print(out_file, new_string(i));
	  if new_string(i) = LF	then --	end	of string
		 exit;
	  end if;
   end loop;			   
					 
end	str_write;




end	txt_util;