jens
2edaa4d7cb
git-svn-id: http://moon:8086/svn/vhdl/trunk@1290 cc03376c-175c-47c8-b038-4cd826a8556b
144 lines
4.7 KiB
VHDL
144 lines
4.7 KiB
VHDL
--*****************************************************************************
|
|
--
|
|
-- Micron Semiconductor Products, Inc.
|
|
--
|
|
-- Copyright 1997, Micron Semiconductor Products, Inc.
|
|
-- All rights reserved.
|
|
--
|
|
--*****************************************************************************
|
|
|
|
LIBRARY work;
|
|
LIBRARY ieee;
|
|
USE ieee.std_logic_1164.ALL;
|
|
|
|
PACKAGE mti_pkg IS
|
|
|
|
FUNCTION TO_INTEGER (input : BIT) RETURN INTEGER;
|
|
FUNCTION TO_INTEGER (input : BIT_VECTOR) RETURN INTEGER;
|
|
FUNCTION TO_INTEGER (input : STD_LOGIC) RETURN INTEGER;
|
|
FUNCTION TO_INTEGER (input : STD_LOGIC_VECTOR) RETURN INTEGER;
|
|
PROCEDURE TO_BITVECTOR (VARIABLE input : IN INTEGER; VARIABLE output : OUT BIT_VECTOR);
|
|
|
|
END mti_pkg;
|
|
|
|
PACKAGE BODY mti_pkg IS
|
|
|
|
-- Convert BIT to INTEGER
|
|
FUNCTION TO_INTEGER (input : BIT) RETURN INTEGER IS
|
|
VARIABLE result : INTEGER := 0;
|
|
VARIABLE weight : INTEGER := 1;
|
|
BEGIN
|
|
IF input = '1' THEN
|
|
result := weight;
|
|
ELSE
|
|
result := 0; -- if unknowns, default to logic 0
|
|
END IF;
|
|
RETURN result;
|
|
END TO_INTEGER;
|
|
|
|
-- Convert BIT_VECTOR to INTEGER
|
|
FUNCTION TO_INTEGER (input : BIT_VECTOR) RETURN INTEGER IS
|
|
VARIABLE result : INTEGER := 0;
|
|
VARIABLE weight : INTEGER := 1;
|
|
BEGIN
|
|
FOR i IN input'LOW TO input'HIGH LOOP
|
|
IF input(i) = '1' THEN
|
|
result := result + weight;
|
|
ELSE
|
|
result := result + 0; -- if unknowns, default to logic 0
|
|
END IF;
|
|
weight := weight * 2;
|
|
END LOOP;
|
|
RETURN result;
|
|
END TO_INTEGER;
|
|
|
|
-- Convert STD_LOGIC to INTEGER
|
|
FUNCTION TO_INTEGER (input : STD_LOGIC) RETURN INTEGER IS
|
|
VARIABLE result : INTEGER := 0;
|
|
VARIABLE weight : INTEGER := 1;
|
|
BEGIN
|
|
IF input = '1' THEN
|
|
result := weight;
|
|
ELSE
|
|
result := 0; -- if unknowns, default to logic 0
|
|
END IF;
|
|
RETURN result;
|
|
END TO_INTEGER;
|
|
|
|
-- Convert STD_LOGIC_VECTOR to INTEGER
|
|
FUNCTION TO_INTEGER (input : STD_LOGIC_VECTOR) RETURN INTEGER IS
|
|
VARIABLE result : INTEGER := 0;
|
|
VARIABLE weight : INTEGER := 1;
|
|
BEGIN
|
|
FOR i IN input'LOW TO input'HIGH LOOP
|
|
IF input(i) = '1' THEN
|
|
result := result + weight;
|
|
ELSE
|
|
result := result + 0; -- if unknowns, default to logic 0
|
|
END IF;
|
|
weight := weight * 2;
|
|
END LOOP;
|
|
RETURN result;
|
|
END TO_INTEGER;
|
|
|
|
-- Conver integer to bit_vector
|
|
PROCEDURE TO_BITVECTOR (VARIABLE input : IN INTEGER; VARIABLE output : OUT BIT_VECTOR) IS
|
|
VARIABLE work,offset,outputlen,j : INTEGER := 0;
|
|
BEGIN
|
|
--length of vector
|
|
IF output'LENGTH > 32 THEN
|
|
outputlen := 32;
|
|
offset := output'LENGTH - 32;
|
|
IF input >= 0 THEN
|
|
FOR i IN offset-1 DOWNTO 0 LOOP
|
|
output(output'HIGH - i) := '0';
|
|
END LOOP;
|
|
ELSE
|
|
FOR i IN offset-1 DOWNTO 0 LOOP
|
|
output(output'HIGH - i) := '1';
|
|
END LOOP;
|
|
END IF;
|
|
ELSE
|
|
outputlen := output'LENGTH;
|
|
END IF;
|
|
--positive value
|
|
IF (input >= 0) THEN
|
|
work := input;
|
|
j := outputlen - 1;
|
|
FOR i IN 1 to 32 LOOP
|
|
IF j >= 0 then
|
|
IF (work MOD 2) = 0 THEN
|
|
output(output'HIGH-j-offset) := '0';
|
|
ELSE
|
|
output(output'HIGH-j-offset) := '1';
|
|
END IF;
|
|
END IF;
|
|
work := work / 2;
|
|
j := j - 1;
|
|
END LOOP;
|
|
IF outputlen = 32 THEN
|
|
output(output'HIGH) := '0';
|
|
END IF;
|
|
--negative value
|
|
ELSE
|
|
work := (-input) - 1;
|
|
j := outputlen - 1;
|
|
FOR i IN 1 TO 32 LOOP
|
|
IF j>= 0 THEN
|
|
IF (work MOD 2) = 0 THEN
|
|
output(output'HIGH-j-offset) := '1';
|
|
ELSE
|
|
output(output'HIGH-j-offset) := '0';
|
|
END IF;
|
|
END IF;
|
|
work := work / 2;
|
|
j := j - 1;
|
|
END LOOP;
|
|
IF outputlen = 32 THEN
|
|
output(output'HIGH) := '1';
|
|
END IF;
|
|
END IF;
|
|
END TO_BITVECTOR;
|
|
|
|
END mti_pkg;
|