tb_uart.vhw

一种实现计算机接口rs232与FPGA通信的基于VHDL语言设计的一段非常简洁的程序

--------------------------------------------------------------------------------
-- Copyright (c) 1995-2003 Xilinx, Inc.
-- All Right Reserved.
--------------------------------------------------------------------------------
--   ____  ____ 
--  /   /\/   / 
-- /___/  \  /    Vendor: Xilinx 
-- \   \   \/     Version : 7.1.04i
--  \   \         Application : ISE Foundation
--  /   /         Filename : tb_uart.vhw
-- /___/   /\     Timestamp : Sun Mar 15 21:55:01 2009
-- \   \  /  \ 
--  \___\/\___\ 
--
--Command: 
--Design Name: tb_uart
--Device: Xilinx
--

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
USE IEEE.STD_LOGIC_TEXTIO.ALL;
USE STD.TEXTIO.ALL;

ENTITY tb_uart IS
END tb_uart;

ARCHITECTURE testbench_arch OF tb_uart IS
    COMPONENT top
        PORT (
            clk32mhz : In std_logic;
            reset : In std_logic;
            rxd : In std_logic;
            xmit_cmd_p_in : In std_logic;
            txdbuf_in : In std_logic_vector (7 DownTo 0);
            rec_ready : Out std_logic;
            txd_out : Out std_logic;
            txd_done_out : Out std_logic;
            clkout : Out std_logic;
            rec_buf : Out std_logic_vector (7 DownTo 0)
        );
    END COMPONENT;

    SIGNAL clk32mhz : std_logic := '0';
    SIGNAL reset : std_logic := '1';
    SIGNAL rxd : std_logic := '0';
    SIGNAL xmit_cmd_p_in : std_logic := '0';
    SIGNAL txdbuf_in : std_logic_vector (7 DownTo 0) := "00000000";
    SIGNAL rec_ready : std_logic := '0';
    SIGNAL txd_out : std_logic := '0';
    SIGNAL txd_done_out : std_logic := '0';
    SIGNAL clkout : std_logic := '0';
    SIGNAL rec_buf : std_logic_vector (7 DownTo 0) := "00000000";

    SHARED VARIABLE TX_ERROR : INTEGER := 0;
    SHARED VARIABLE TX_OUT : LINE;

    constant PERIOD : time := 200 ns;
    constant DUTY_CYCLE : real := 0.5;
    constant OFFSET : time := 0 ns;

    BEGIN
        UUT : top
        PORT MAP (
            clk32mhz => clk32mhz,
            reset => reset,
            rxd => rxd,
            xmit_cmd_p_in => xmit_cmd_p_in,
            txdbuf_in => txdbuf_in,
            rec_ready => rec_ready,
            txd_out => txd_out,
            txd_done_out => txd_done_out,
            clkout => clkout,
            rec_buf => rec_buf
        );

        PROCESS    -- clock process for clk32mhz
        BEGIN
            WAIT for OFFSET;
            CLOCK_LOOP : LOOP
                clk32mhz <= '0';
                WAIT FOR (PERIOD - (PERIOD * DUTY_CYCLE));
                clk32mhz <= '1';
                WAIT FOR (PERIOD * DUTY_CYCLE);
            END LOOP CLOCK_LOOP;
        END PROCESS;

        PROCESS
            PROCEDURE CHECK_clkout(
                next_clkout : std_logic;
                TX_TIME : INTEGER
            ) IS
                VARIABLE TX_STR : String(1 to 4096);
                VARIABLE TX_LOC : LINE;
                BEGIN
                IF (clkout /= next_clkout) THEN
                    STD.TEXTIO.write(TX_LOC, string'("Error at time="));
                    STD.TEXTIO.write(TX_LOC, TX_TIME);
                    STD.TEXTIO.write(TX_LOC, string'("ns clkout="));
                    IEEE.STD_LOGIC_TEXTIO.write(TX_LOC, clkout);
                    STD.TEXTIO.write(TX_LOC, string'(", Expected = "));
                    IEEE.STD_LOGIC_TEXTIO.write(TX_LOC, next_clkout);
                    STD.TEXTIO.write(TX_LOC, string'(" "));
                    TX_STR(TX_LOC.all'range) := TX_LOC.all;
                    STD.TEXTIO.Deallocate(TX_LOC);
                    ASSERT (FALSE) REPORT TX_STR SEVERITY ERROR;
                    TX_ERROR := TX_ERROR + 1;
                END IF;
            END;
            PROCEDURE CHECK_rec_buf(
                next_rec_buf : std_logic_vector (7 DownTo 0);
                TX_TIME : INTEGER
            ) IS
                VARIABLE TX_STR : String(1 to 4096);
                VARIABLE TX_LOC : LINE;
                BEGIN
                IF (rec_buf /= next_rec_buf) THEN
                    STD.TEXTIO.write(TX_LOC, string'("Error at time="));
                    STD.TEXTIO.write(TX_LOC, TX_TIME);
                    STD.TEXTIO.write(TX_LOC, string'("ns rec_buf="));
                    IEEE.STD_LOGIC_TEXTIO.write(TX_LOC, rec_buf);
                    STD.TEXTIO.write(TX_LOC, string'(", Expected = "));
                    IEEE.STD_LOGIC_TEXTIO.write(TX_LOC, next_rec_buf);
                    STD.TEXTIO.write(TX_LOC, string'(" "));
                    TX_STR(TX_LOC.all'range) := TX_LOC.all;
                    STD.TEXTIO.Deallocate(TX_LOC);
                    ASSERT (FALSE) REPORT TX_STR SEVERITY ERROR;
                    TX_ERROR := TX_ERROR + 1;
                END IF;
            END;
            PROCEDURE CHECK_rec_ready(
                next_rec_ready : std_logic;
                TX_TIME : INTEGER
            ) IS
                VARIABLE TX_STR : String(1 to 4096);
                VARIABLE TX_LOC : LINE;
                BEGIN
                IF (rec_ready /= next_rec_ready) THEN
                    STD.TEXTIO.write(TX_LOC, string'("Error at time="));
                    STD.TEXTIO.write(TX_LOC, TX_TIME);
                    STD.TEXTIO.write(TX_LOC, string'("ns rec_ready="));
                    IEEE.STD_LOGIC_TEXTIO.write(TX_LOC, rec_ready);
                    STD.TEXTIO.write(TX_LOC, string'(", Expected = "));
                    IEEE.STD_LOGIC_TEXTIO.write(TX_LOC, next_rec_ready);
                    STD.TEXTIO.write(TX_LOC, string'(" "));
                    TX_STR(TX_LOC.all'range) := TX_LOC.all;
                    STD.TEXTIO.Deallocate(TX_LOC);
                    ASSERT (FALSE) REPORT TX_STR SEVERITY ERROR;
                    TX_ERROR := TX_ERROR + 1;
                END IF;
            END;
            PROCEDURE CHECK_txd_done_out(
                next_txd_done_out : std_logic;
                TX_TIME : INTEGER
            ) IS
                VARIABLE TX_STR : String(1 to 4096);
                VARIABLE TX_LOC : LINE;
                BEGIN
                IF (txd_done_out /= next_txd_done_out) THEN
                    STD.TEXTIO.write(TX_LOC, string'("Error at time="));
                    STD.TEXTIO.write(TX_LOC, TX_TIME);
                    STD.TEXTIO.write(TX_LOC, string'("ns txd_done_out="));
                    IEEE.STD_LOGIC_TEXTIO.write(TX_LOC, txd_done_out);
                    STD.TEXTIO.write(TX_LOC, string'(", Expected = "));
                    IEEE.STD_LOGIC_TEXTIO.write(TX_LOC, next_txd_done_out);
                    STD.TEXTIO.write(TX_LOC, string'(" "));
                    TX_STR(TX_LOC.all'range) := TX_LOC.all;
                    STD.TEXTIO.Deallocate(TX_LOC);
                    ASSERT (FALSE) REPORT TX_STR SEVERITY ERROR;
                    TX_ERROR := TX_ERROR + 1;
                END IF;
            END;
            PROCEDURE CHECK_txd_out(
                next_txd_out : std_logic;
                TX_TIME : INTEGER
            ) IS
                VARIABLE TX_STR : String(1 to 4096);
                VARIABLE TX_LOC : LINE;
                BEGIN
                IF (txd_out /= next_txd_out) THEN
                    STD.TEXTIO.write(TX_LOC, string'("Error at time="));
                    STD.TEXTIO.write(TX_LOC, TX_TIME);
                    STD.TEXTIO.write(TX_LOC, string'("ns txd_out="));
                    IEEE.STD_LOGIC_TEXTIO.write(TX_LOC, txd_out);
                    STD.TEXTIO.write(TX_LOC, string'(", Expected = "));
                    IEEE.STD_LOGIC_TEXTIO.write(TX_LOC, next_txd_out);
                    STD.TEXTIO.write(TX_LOC, string'(" "));
                    TX_STR(TX_LOC.all'range) := TX_LOC.all;
                    STD.TEXTIO.Deallocate(TX_LOC);
                    ASSERT (FALSE) REPORT TX_STR SEVERITY ERROR;
                    TX_ERROR := TX_ERROR + 1;
                END IF;
            END;
            BEGIN
                -- -------------  Current Time:  285ns
                WAIT FOR 285 ns;
                txdbuf_in <= "00000001";
                -- -------------------------------------
                -- -------------  Current Time:  485ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00000010";
                -- -------------------------------------
                -- -------------  Current Time:  685ns
                WAIT FOR 200 ns;
                reset <= '0';
                txdbuf_in <= "00000011";
                -- -------------------------------------
                -- -------------  Current Time:  885ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00000100";
                -- -------------------------------------
                -- -------------  Current Time:  1085ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00000101";
                -- -------------------------------------
                -- -------------  Current Time:  1285ns
                WAIT FOR 200 ns;
                xmit_cmd_p_in <= '1';
                txdbuf_in <= "00000110";
                -- -------------------------------------
                -- -------------  Current Time:  1485ns
                WAIT FOR 200 ns;
                rxd <= '1';
                txdbuf_in <= "00000111";
                -- -------------------------------------
                -- -------------  Current Time:  1685ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00001000";
                -- -------------------------------------
                -- -------------  Current Time:  1885ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00001001";
                -- -------------------------------------
                -- -------------  Current Time:  2085ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00001010";
                -- -------------------------------------
                -- -------------  Current Time:  2285ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00001011";
                -- -------------------------------------
                -- -------------  Current Time:  2485ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00001100";
                -- -------------------------------------
                -- -------------  Current Time:  2685ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00001101";
                -- -------------------------------------
                -- -------------  Current Time:  2885ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00001110";
                -- -------------------------------------
                -- -------------  Current Time:  3085ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00001111";
                -- -------------------------------------
                -- -------------  Current Time:  3285ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00010000";
                -- -------------------------------------
                -- -------------  Current Time:  3485ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00010001";
                -- -------------------------------------
                -- -------------  Current Time:  3685ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00010010";
                -- -------------------------------------
                -- -------------  Current Time:  3885ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00010011";
                -- -------------------------------------
                -- -------------  Current Time:  4085ns
                WAIT FOR 200 ns;
                txdbuf_in <= "00010100";
                -- -------------------------------------
                -- -------------  Current Time:  4285ns