uart.vhd

一些基本的DSP子程序

--    File Name:  uart.vhd
--      Version:  1.1
--         Date:  January 22, 2000
--        Model:  Uart Chip
-- Dependencies:  txmit.hd, rcvr.vhd
--
--      Company:  Xilinx
--
--
--   Disclaimer:  THESE DESIGNS ARE PROVIDED "AS IS" WITH NO WARRANTY 
--                WHATSOEVER AND XILINX SPECIFICALLY DISCLAIMS ANY 
--                IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
--                A PARTICULAR PURPOSE, OR AGAINST INFRINGEMENT.
--
--                Copyright (c) 2000 Xilinx, Inc.
--                All rights reserved


library ieee;
use ieee.std_logic_1164.all ;
use ieee.std_logic_arith.all ;
use ieee.std_logic_unsigned.all ;

entity uart is
PORT (rst,clk16x,rxd,rdn,wrn,csn: in std_logic;
din : in std_logic_vector(7 downto 0);
dout: out std_logic_vector(7 downto 0);
data_ready : out std_logic;
parity_error : out std_logic;
framing_error : out std_logic;
tdempty : out std_logic;
tsre : out std_logic;
sdo :out std_logic;
ndo_en : out std_logic);
end uart;

architecture v1 of uart is

signal iwrn:std_logic;
signal irdn:std_logic;
component txmit 
port (rst,clk16x,wrn : in std_logic;
din : in std_logic_vector(7 downto 0);
tdempty,tsre,sdo: out std_logic);
end component ;

component rcvr 
port (rst,clk16x,rxd,rdn : in std_logic;
data_ready, parity_error, framing_error : out std_logic;
dout : out std_logic_vector(7 downto 0));
end component ;
begin
   
u1 : txmit PORT MAP 
(rst => rst,
clk16x => clk16x,
wrn => iwrn,
din => din,
tdempty => tdempty,
tsre => tsre,
sdo => sdo);

u2 : rcvr PORT MAP  
(rst => rst,
clk16x => clk16x,
rxd => rxd,
rdn => irdn,
data_ready => data_ready,
framing_error => framing_error,
parity_error => parity_error,
dout => dout) ;
iwrn<=csn or wrn;
irdn<=csn or rdn;
ndo_en<=csn or rdn;
end v1 ;