VHDL 整数到字符串

Question

想象一下，您想在 VHDL 中将整数转换为字符串以在 VGA 监视器上显示。您不能使用 ieee 2008 标准，因为您必须使用 xilinx ISE 14.7。我有以下代码用于将整数类型转换为字符串类型，但在 while 循环和 for 循环中出现“超出非静态循环限制”错误：

-- convert integer to string using specified base
-- (adapted from Steve Vogwell's posting in comp.lang.vhdl)

function str(int: integer; base: integer) return string is

variable temp:      string(1 to 10);
variable num:       integer;
variable abs_int:   integer;
variable len:       integer := 1;
variable power:     integer := 1;

begin

-- bug fix for negative numbers
abs_int := abs(int);

num     := abs_int;

while num >= base loop                     -- Determine how many
  len := len + 1;                          -- characters required
  num := num / base;                       -- to represent the
end loop ;                                 -- number.

for i in len downto 1 loop                 -- Convert the number to
  temp(i) := chr(abs_int/power mod base);  -- a string starting
  power := power * base;                   -- with the right hand
end loop ;                                 -- side.

-- return result and add sign if required
if int < 0 then
   return '-'& temp(1 to len);
 else
   return temp(1 to len);
end if;

end str;

我通过将其变形为这个怪物来“解决”错误：

-- convert integer to string using specified base
-- (adapted from Steve Vogwell's posting in comp.lang.vhdl)

function str(int: integer; base: integer) return string is

    variable temp:      string(1 to 9);
    variable num:       integer;
    variable abs_int:   integer;
    variable len:       integer := 1;
    variable power:     integer := 1;

    begin

    -- bug fix for negative numbers
    abs_int := abs(int);

    num     := abs_int;

    for i in 0 to 100 loop
        if (num >= base) then                   -- Determine how many
          len := len + 1;                       -- characters required
          num := num / base;                    -- to represent the
        else                                    -- number.
            exit;
        end if;
    end loop ;                                 

    for i in 9 downto 1 loop                 -- Convert the number to
        if (i <= len) then
            temp(i) := chr(abs_int/power mod base);  -- a string starting
            power := power * base;                   -- with the right hand
        else
            exit;
        end if;
    end loop ;                                 -- side.

    -- return result and add sign if required
    if int < 0 then
       return '-'& temp(1 to len);
     else
       return temp(1 to len);
    end if;

end str;

是否有将整数转换为字符串的非延迟方法？

Answer 1

如果I是整数，则将integer'image(I)其表示为字符串。