-------------------------------------------------------------------------------
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-- O R E G A N O S Y S T E M S --
-- --
-- Design & Consulting --
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-------------------------------------------------------------------------------
-- --
-- Web: http://www.oregano.at/ --
-- --
-- Contact: mc8051@oregano.at --
-- --
-------------------------------------------------------------------------------
-- --
-- MC8051 - VHDL 8051 Microcontroller IP Core --
-- Copyright (C) 2001 OREGANO SYSTEMS --
-- --
-- This library is free software; you can redistribute it and/or --
-- modify it under the terms of the GNU Lesser General Public --
-- License as published by the Free Software Foundation; either --
-- version 2.1 of the License, or (at your option) any later version. --
-- --
-- This library is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY; without even the implied warranty of --
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-- Lesser General Public License for more details. --
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-- --
-------------------------------------------------------------------------------
--
--
-- Author: Roland H鰈ler
--
-- Filename: comb_divider_rtl.vhd
--
-- Date of Creation: Mon Aug 9 12:14:48 1999
--
-- Version: $Revision: 1.4 $
--
-- Date of Latest Version: $Date: 2002/01/07 12:17:44 $
--
--
-- Description: Divider with parameteriseable data width. Realised
-- using combinational logic only.
--
--
--
--
-------------------------------------------------------------------------------
architecture rtl of comb_divider is
begin -- rtl
-- purpose: Divide dvdnd_i through dvsor_i and deliver the result to qutnt_o
-- and the remainder to rmndr_o.
-- type : combinational
-- inputs : dvdnd_i, dvsor_i
-- outputs: qutnt_o, rmndr_o
p_divide: process (dvdnd_i, dvsor_i)
variable v_actl_dvdnd : unsigned(DWIDTH-1 downto 0);
variable v_dffrnc : unsigned(DWIDTH-1 downto 0);
variable v_qutnt : unsigned(DWIDTH-1 downto 0);
begin -- process p_divide
v_actl_dvdnd := unsigned(dvdnd_i);
for i in DWIDTH-1 downto 0 loop
-- If the divisor can be subtracted from this part of the dividend, then
-- the corresponding bit of the quotient has to be 1, otherwise 0.
if conv_std_logic_vector(v_actl_dvdnd(DWIDTH-1 downto i),DWIDTH) >=
dvsor_i then
-- Divisor can be subtracted
v_qutnt(i) := '1';
v_dffrnc := conv_unsigned(v_actl_dvdnd(DWIDTH-1 downto i),DWIDTH)
- unsigned(dvsor_i);
-- As long as this is not the last step of calculation, shift the
-- intermediate result.
if i /= 0 then
v_actl_dvdnd(DWIDTH-1 downto i) := v_dffrnc(DWIDTH-1-i downto 0);
v_actl_dvdnd(i-1) := dvdnd_i(i-1);
end if;
else
-- Divisor is greater than this part of the dividend.
v_qutnt(i) := '0';
v_dffrnc := conv_unsigned(v_actl_dvdnd(DWIDTH-1 downto i),DWIDTH);
end if;
end loop; -- i
rmndr_o qutnt_o
end process p_divide;
end rtl;
