UART.vhd
98 lines
| 3.9 KiB
| text/x-vhdl
|
VhdlLexer
Alexis
|
r19 | ------------------------------------------------------------------------------ | ||
-- This file is a part of the LPP VHDL IP LIBRARY | ||||
-- Copyright (C) 2009 - 2010, Laboratory of Plasmas Physic - CNRS | ||||
-- | ||||
-- This program is free software; you can redistribute it and/or modify | ||||
-- it under the terms of the GNU General Public License as published by | ||||
-- the Free Software Foundation; either version 3 of the License, or | ||||
-- (at your option) any later version. | ||||
-- | ||||
-- This program is distributed in the hope that it will be useful, | ||||
-- but WITHOUT ANY WARRANTY; without even the implied warranty of | ||||
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||||
-- GNU General Public License for more details. | ||||
-- | ||||
-- You should have received a copy of the GNU General Public License | ||||
-- along with this program; if not, write to the Free Software | ||||
-- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||||
------------------------------------------------------------------------------- | ||||
library IEEE; | ||||
use IEEE.numeric_std.all; | ||||
use IEEE.std_logic_1164.all; | ||||
library lpp; | ||||
use lpp.lpp_uart.all; | ||||
--! Programme qui va gerer toute la communication entre le PC et le FPGA | ||||
entity UART is | ||||
generic(Data_sz : integer := 8); --! Constante de taille pour un mot de donnee | ||||
port( | ||||
clk : in std_logic; --! Horloge a 25Mhz du systeme | ||||
reset : in std_logic; --! Reset du systeme | ||||
TXD : out std_logic; --! Transmission, cote PC | ||||
RXD : in std_logic; --! Reception, cote PC | ||||
Capture : in std_logic; --! "Reset" cible pour le generateur de bauds, ici indissocie du reset global | ||||
NwDat : out std_logic; --! Flag, Nouvelle donnee presente | ||||
ACK : in std_logic; --! Flag, Reponse au flag precedent | ||||
Send : in std_logic; --! Flag, Demande d'envoi sur le bus | ||||
Sended : out std_logic; --! Flag, Envoi termine | ||||
BTrigger : out std_logic_vector(11 downto 0); --! Registre contenant la valeur du diviseur de frequence pour la transmission | ||||
RDATA : out std_logic_vector(Data_sz-1 downto 0); --! Mot de donnee en provenance de l'utilisateur | ||||
WDATA : in std_logic_vector(Data_sz-1 downto 0) --! Mot de donnee a transmettre a l'utilisateur | ||||
); | ||||
end entity; | ||||
--! @details Gestion de la Reception/Transmission donc de la Vectorisation/Serialisation | ||||
--! ainsi que la detection et le reglage de le frequence de transmission optimale sur le bus (Generateur de Bauds) | ||||
architecture ar_UART of UART is | ||||
signal Bclk : std_logic; | ||||
signal RDATA_int : std_logic_vector(Data_sz+1 downto 0); | ||||
signal WDATA_int : std_logic_vector(Data_sz+1 downto 0); | ||||
signal TXD_Dummy : std_logic; | ||||
signal NwDat_int : std_logic; | ||||
signal NwDat_int_reg : std_logic; | ||||
signal receive : std_logic; | ||||
begin | ||||
RDATA <= RDATA_int(8 downto 1); | ||||
WDATA_int <= '1' & WDATA & '0'; | ||||
BaudGenerator : BaudGen | ||||
port map(clk,reset,Capture,Bclk,RXD,BTrigger); | ||||
RX_REG : Shift_REG | ||||
generic map(Data_sz+2) | ||||
port map(clk,Bclk,reset,RXD,TXD_Dummy,receive,NwDat_int,(others => '0'),RDATA_int); | ||||
TX_REG : Shift_REG | ||||
generic map(Data_sz+2) | ||||
port map(clk,Bclk,reset,'1',TXD,Send,Sended,WDATA_int); | ||||
process(clk,reset) | ||||
begin | ||||
if reset = '0' then | ||||
NwDat <= '0'; | ||||
elsif clk'event and clk = '1' then | ||||
NwDat_int_reg <= NwDat_int; | ||||
if RXD = '1' and NwDat_int = '1' then | ||||
receive <= '0'; | ||||
elsif RXD = '0' then | ||||
receive <= '1'; | ||||
end if; | ||||
if NwDat_int_reg = '0' and NwDat_int = '1' then | ||||
NwDat <= '1'; | ||||
elsif ack = '1' then | ||||
NwDat <= '0'; | ||||
end if; | ||||
end if; | ||||
end process; | ||||
end ar_UART; | ||||