57 lines
1.9 KiB
VHDL
57 lines
1.9 KiB
VHDL
|
-- This package should cover general useful functions that
|
||
|
|
-- will see a lot of use in my code but do not fit under
|
||
|
|
-- any specific umbrella.
|
||
|
|
|
||
|
|
library ieee;
|
||
|
|
use ieee.std_logic_1164.all;
|
||
|
|
use ieee.numeric_std.all;
|
||
|
|
|
||
|
|
package useful_functions_pkg is
|
||
|
|
|
||
|
|
function extend(input : unsigned; length : natural) return unsigned;
|
||
|
|
function extend(input : std_logic_vector; length : natural) return std_logic_vector;
|
||
|
|
function extend(input : std_logic; length : natural) return std_logic_vector;
|
||
|
|
|
||
|
|
end package;
|
||
|
|
|
||
|
|
package body useful_functions_pkg is
|
||
|
|
|
||
|
|
function extend(input : unsigned; length : natural) return unsigned is
|
||
|
|
variable returned_vector : unsigned(length - 1 downto 0);
|
||
|
|
begin
|
||
|
|
if length >= input'length then
|
||
|
|
returned_vector(returned_vector'high downto input'length) := (others => '0');
|
||
|
|
returned_vector(input'length - 1 downto 0) := input;
|
||
|
|
else
|
||
|
|
returned_vector := input(returned_vector'length - 1 downto 0);
|
||
|
|
end if;
|
||
|
|
|
||
|
|
return returned_vector;
|
||
|
|
end function extend;
|
||
|
|
|
||
|
|
function extend(input : std_logic_vector; length : natural) return std_logic_vector is
|
||
|
|
variable returned_vector : std_logic_vector(length - 1 downto 0);
|
||
|
|
begin
|
||
|
|
if length >= input'length then
|
||
|
|
returned_vector(returned_vector'high downto input'length) := (others => '0');
|
||
|
|
returned_vector(input'length - 1 downto 0) := input;
|
||
|
|
else
|
||
|
|
returned_vector := input(returned_vector'length - 1 downto 0);
|
||
|
|
end if;
|
||
|
|
|
||
|
|
return returned_vector;
|
||
|
|
end function extend;
|
||
|
|
|
||
|
|
function extend(input : std_logic; length : natural) return std_logic_vector is
|
||
|
|
variable returned_vector : std_logic_vector(length - 1 downto 0);
|
||
|
|
begin
|
||
|
|
if length >= 1 then
|
||
|
|
returned_vector(length - 1 downto 1) := (others => '0');
|
||
|
|
returned_vector(0) := input;
|
||
|
|
end if;
|
||
|
|
|
||
|
|
return returned_vector;
|
||
|
|
|
||
|
|
end function extend;
|
||
|
|
|
||
|
|
end package body;
|