--
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--
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-- PIC16xx compatible microcontroller core
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-- PIC16xx compatible microcontroller core
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--
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--
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-- Version : 0222
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-- Version : 0222
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--
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--
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-- Copyright (c) 2001-2002 Daniel Wallner (jesus@opencores.org)
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-- Copyright (c) 2001-2002 Daniel Wallner (jesus@opencores.org)
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--
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--
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-- All rights reserved
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-- All rights reserved
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--
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--
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-- Redistribution and use in source and synthezised forms, with or without
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-- Redistribution and use in source and synthezised forms, with or without
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-- modification, are permitted provided that the following conditions are met:
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-- modification, are permitted provided that the following conditions are met:
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--
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--
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-- Redistributions of source code must retain the above copyright notice,
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-- Redistributions of source code must retain the above copyright notice,
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-- this list of conditions and the following disclaimer.
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-- this list of conditions and the following disclaimer.
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--
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--
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-- Redistributions in synthesized form must reproduce the above copyright
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-- Redistributions in synthesized form must reproduce the above copyright
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-- notice, this list of conditions and the following disclaimer in the
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-- notice, this list of conditions and the following disclaimer in the
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-- documentation and/or other materials provided with the distribution.
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-- documentation and/or other materials provided with the distribution.
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--
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--
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-- Neither the name of the author nor the names of other contributors may
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-- Neither the name of the author nor the names of other contributors may
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-- be used to endorse or promote products derived from this software without
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-- be used to endorse or promote products derived from this software without
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-- specific prior written permission.
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-- specific prior written permission.
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--
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--
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-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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-- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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-- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
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-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
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-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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-- POSSIBILITY OF SUCH DAMAGE.
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-- POSSIBILITY OF SUCH DAMAGE.
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--
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--
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-- Please report bugs to the author, but before you do so, please
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-- Please report bugs to the author, but before you do so, please
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-- make sure that this is not a derivative work and that
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-- make sure that this is not a derivative work and that
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-- you have the latest version of this file.
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-- you have the latest version of this file.
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--
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--
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-- The latest version of this file can be found at:
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-- The latest version of this file can be found at:
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-- http://www.opencores.org/cvsweb.shtml/t51/
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-- http://www.opencores.org/cvsweb.shtml/t51/
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--
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--
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-- Limitations :
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-- Limitations :
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--
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--
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-- File history :
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-- File history :
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--
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--
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library IEEE;
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library IEEE;
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use IEEE.std_logic_1164.all;
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use IEEE.std_logic_1164.all;
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use IEEE.numeric_std.all;
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use IEEE.numeric_std.all;
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entity PPX_PCS is
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entity PPX_PCS is
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generic(
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generic(
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PC_Width : integer;
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PC_Width : integer;
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StackAddrWidth : integer;
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StackAddrWidth : integer;
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TopBoot : boolean
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TopBoot : boolean
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);
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);
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port(
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port(
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Clk : in std_logic;
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Clk : in std_logic;
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Reset_n : in std_logic;
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Reset_n : in std_logic;
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CS : in std_logic;
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CS : in std_logic;
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Wr : in std_logic;
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Wr : in std_logic;
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Data_In : in std_logic_vector(7 downto 0);
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Data_In : in std_logic_vector(7 downto 0);
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Addr_In : in std_logic_vector(PC_Width - 3 downto 0);
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Addr_In : in std_logic_vector(PC_Width - 3 downto 0);
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PCLATH : in std_logic_vector(4 downto 0);
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PCLATH : in std_logic_vector(4 downto 0);
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STATUS : in std_logic_vector(6 downto 5);
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STATUS : in std_logic_vector(6 downto 5);
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NPC : out std_logic_vector(PC_Width - 1 downto 0);
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NPC : out std_logic_vector(PC_Width - 1 downto 0);
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Int : in std_logic;
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Int : in std_logic;
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Sleep : in std_logic;
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Sleep : in std_logic;
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Push : in std_logic;
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Push : in std_logic;
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Pop : in std_logic;
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Pop : in std_logic;
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Goto : in std_logic
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Goto : in std_logic
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);
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);
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end PPX_PCS;
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end PPX_PCS;
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architecture rtl of PPX_PCS is
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architecture rtl of PPX_PCS is
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signal PC_i : unsigned(PC_Width - 1 downto 0);
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signal PC_i : unsigned(PC_Width - 1 downto 0);
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signal NPC_i : unsigned(PC_Width - 1 downto 0);
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signal NPC_i : unsigned(PC_Width - 1 downto 0);
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type Stack_Image is array (2 ** StackAddrWidth - 1 downto 0) of unsigned(PC_Width - 1 downto 0);
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type Stack_Image is array (2 ** StackAddrWidth - 1 downto 0) of unsigned(PC_Width - 1 downto 0);
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signal Stack : Stack_Image;
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signal Stack : Stack_Image;
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signal StackPtr : unsigned(StackAddrWidth -1 downto 0);
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signal StackPtr : unsigned(StackAddrWidth -1 downto 0);
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begin
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begin
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NPC <= std_logic_vector(NPC_i);
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NPC <= std_logic_vector(NPC_i);
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process (Clk)
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process (Clk)
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begin
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begin
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if Clk'event and Clk = '1' then
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if Clk'event and Clk = '1' then
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if Push = '1' then
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if Push = '1' then
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Stack(to_integer(StackPtr)) <= PC_i;
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Stack(to_integer(StackPtr)) <= PC_i;
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end if;
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end if;
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if Int = '1' then
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if Int = '1' then
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Stack(to_integer(StackPtr)) <= PC_i - 1;
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Stack(to_integer(StackPtr)) <= PC_i - 1;
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end if;
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end if;
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end if;
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end if;
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end process;
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end process;
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process (PC_i, Sleep, CS, Wr, PCLATH, STATUS, Push, Pop, Goto, Data_In, Addr_In, Int, Stack, StackPtr)
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process (PC_i, Sleep, CS, Wr, PCLATH, STATUS, Push, Pop, Goto, Data_In, Addr_In, Int, Stack, StackPtr)
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begin
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begin
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NPC_i <= PC_i;
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NPC_i <= PC_i;
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if Sleep = '0' then
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if Sleep = '0' then
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NPC_i <= PC_i + 1;
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NPC_i <= PC_i + 1;
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end if;
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end if;
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if CS = '1' and Wr = '1' then
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if CS = '1' and Wr = '1' then
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if PC_Width = 13 then
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if PC_Width = 13 then
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NPC_i(7 downto 0) <= unsigned(Data_In);
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NPC_i(7 downto 0) <= unsigned(Data_In);
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NPC_i(PC_Width - 1 downto PC_Width - 5) <= unsigned(PCLATH);
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NPC_i(PC_Width - 1 downto PC_Width - 5) <= unsigned(PCLATH);
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end if;
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end if;
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if PC_Width = 11 then
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if PC_Width = 11 then
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NPC_i(7 downto 0) <= unsigned(Data_In);
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NPC_i(7 downto 0) <= unsigned(Data_In);
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NPC_i(8) <= '0';
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NPC_i(8) <= '0';
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NPC_i(10 downto 9) <= unsigned(STATUS);
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NPC_i(10 downto 9) <= unsigned(STATUS);
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end if;
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end if;
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end if;
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end if;
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if Push = '1' then
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if Push = '1' then
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if PC_Width = 13 then
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if PC_Width = 13 then
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NPC_i(10 downto 0) <= unsigned(Addr_In);
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NPC_i(10 downto 0) <= unsigned(Addr_In);
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NPC_i(PC_Width - 1 downto PC_Width - 2) <= unsigned(PCLATH(4 downto 3));
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NPC_i(PC_Width - 1 downto PC_Width - 2) <= unsigned(PCLATH(4 downto 3));
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end if;
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end if;
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if PC_Width = 11 then
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if PC_Width = 11 then
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NPC_i(7 downto 0) <= unsigned(Addr_In(7 downto 0));
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NPC_i(7 downto 0) <= unsigned(Addr_In(7 downto 0));
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NPC_i(8) <= '0';
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NPC_i(8) <= '0';
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NPC_i(10 downto 9) <= unsigned(STATUS);
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NPC_i(10 downto 9) <= unsigned(STATUS);
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end if;
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end if;
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end if;
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end if;
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if Pop = '1' then
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if Pop = '1' then
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NPC_i <= Stack(to_integer(StackPtr - 1));
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NPC_i <= Stack(to_integer(StackPtr - 1));
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end if;
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end if;
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if Goto = '1' then
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if Goto = '1' then
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if PC_Width = 13 then
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if PC_Width = 13 then
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NPC_i(10 downto 0) <= unsigned(Addr_In);
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NPC_i(10 downto 0) <= unsigned(Addr_In);
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NPC_i(PC_Width - 1 downto PC_Width - 2) <= unsigned(PCLATH(4 downto 3));
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NPC_i(PC_Width - 1 downto PC_Width - 2) <= unsigned(PCLATH(4 downto 3));
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end if;
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end if;
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if PC_Width = 11 then
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if PC_Width = 11 then
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NPC_i(8 downto 0) <= unsigned(Addr_In);
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NPC_i(8 downto 0) <= unsigned(Addr_In);
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NPC_i(10 downto 9) <= unsigned(STATUS);
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NPC_i(10 downto 9) <= unsigned(STATUS);
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end if;
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end if;
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end if;
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end if;
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if Int = '1' then
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if Int = '1' then
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NPC_i <= (others => '0');
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NPC_i <= (others => '0');
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NPC_i(2) <= '1';
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NPC_i(2) <= '1';
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end if;
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end if;
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end process;
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end process;
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process (Reset_n, Clk)
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process (Reset_n, Clk)
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begin
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begin
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if Reset_n = '0' then
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if Reset_n = '0' then
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PC_i <= (others => '1');
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PC_i <= (others => '1');
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if TopBoot then
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if TopBoot then
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PC_i(0) <= '0';
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PC_i(0) <= '0';
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end if;
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end if;
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StackPtr <= (others => '0');
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StackPtr <= (others => '0');
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elsif Clk'event and Clk = '1' then
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elsif Clk'event and Clk = '1' then
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PC_i <= NPC_i;
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PC_i <= NPC_i;
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if Push = '1' then
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if Push = '1' then
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StackPtr <= StackPtr + 1;
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StackPtr <= StackPtr + 1;
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end if;
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end if;
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if Pop = '1' then
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if Pop = '1' then
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StackPtr <= StackPtr - 1;
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StackPtr <= StackPtr - 1;
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end if;
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end if;
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if Int = '1' then
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if Int = '1' then
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StackPtr <= StackPtr + 1;
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StackPtr <= StackPtr + 1;
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end if;
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end if;
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end if;
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end if;
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end process;
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end process;
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end;
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end;
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