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jidan |
-------------------------------------------------------------------------------
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--
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-- Project: <Floating Point Unit Core>
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--
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-- Description: FPU package wich contains constants and functions needed in the FPU core
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-------------------------------------------------------------------------------
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--
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-- 100101011010011100100
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-- 110000111011100100000
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-- 100000111011000101101
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-- 100010111100101111001
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-- 110000111011101101001
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-- 010000001011101001010
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-- 110100111001001100001
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-- 110111010000001100111
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-- 110110111110001011101
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-- 101110110010111101000
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-- 100000010111000000000
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--
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-- Author: Jidan Al-eryani
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-- E-mail: jidan@gmx.net
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--
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-- Copyright (C) 2006
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--
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-- This source file may be used and distributed without
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-- restriction provided that this copyright statement is not
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-- removed from the file and that any derivative work contains
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-- the original copyright notice and the associated disclaimer.
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--
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-- THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY
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-- EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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-- TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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-- FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR
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-- OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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-- INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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-- (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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-- GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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-- BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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-- LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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-- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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-- OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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-- POSSIBILITY OF SUCH DAMAGE.
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--
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library ieee;
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use ieee.std_logic_1164.all;
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use ieee.std_logic_unsigned.all;
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package fpupack is
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-- Data width of floating-point number. Deafult: 32
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constant FP_WIDTH : integer := 32;
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-- Data width of fraction. Deafult: 23
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constant FRAC_WIDTH : integer := 23;
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-- Data width of exponent. Deafult: 8
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constant EXP_WIDTH : integer := 8;
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-- Infinty FP format
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constant INF : std_logic_vector(30 downto 0) := "1111111100000000000000000000000";
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-- QNaN (Quit Not a Number) FP format (without sign bit)
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constant QNAN : std_logic_vector(30 downto 0) := "1111111110000000000000000000001";
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-- SNaN (Signaling Not a Number) FP format (without sign bit)
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constant SNAN : std_logic_vector(30 downto 0) := "1111111100000000000000000000001";
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-- count the zeros starting from left
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function count_l_zeros (signal s_vector: std_logic_vector) return std_logic_vector;
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-- count the zeros starting from right
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function count_r_zeros (signal s_vector: std_logic_vector) return std_logic_vector;
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end fpupack;
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package body fpupack is
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-- count the zeros starting from left
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function count_l_zeros (signal s_vector: std_logic_vector) return std_logic_vector is
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variable v_count : std_logic_vector(5 downto 0);
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begin
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v_count := "000000";
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for i in s_vector'range loop
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case s_vector(i) is
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when '0' => v_count := v_count + "000001";
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when others => exit;
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end case;
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end loop;
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return v_count;
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end count_l_zeros;
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-- count the zeros starting from right
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function count_r_zeros (signal s_vector: std_logic_vector) return std_logic_vector is
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variable v_count : std_logic_vector(5 downto 0);
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begin
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v_count := "000000";
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for i in 0 to s_vector'length-1 loop
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case s_vector(i) is
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when '0' => v_count := v_count + "000001";
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when others => exit;
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end case;
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end loop;
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return v_count;
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end count_r_zeros;
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end fpupack;
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