35_bus_test.vhd

这是一个对于初学者很好的vhdl实验的一些例子,希望站长的支持哦

library ieee;
use ieee.std_logic_1164.all;
use work.bit_pack.all;
use std.textio.all;

entity tester is
  port ( address,w_data:out bit_vector(31 downto 0);
         r_data:in bit_vector(31 downto 0):=(others =>'0');
         clk,wr,br:out bit;
         std，done:in bit:='0');
end  tester;

architecture test1 of tester is 
   --设定时钟周期为20 ns
   constant half_period: time:=10 ns;
   signal testclk :bit :='1';
begin
  testclk<=not testclk after half_period;
  clk<=testclk after 1 ns;

  read_test_file :process(testclk)
     --已读的方式打开test类型文件"test2.dat"
     --文件名为test_file
     file test_file:text is in "test2.dat";
     variable buff:line;
     variable dataint,addrint:integer;
     variable new_wr,new_br :bit;
  begin
     --当总线处理完成且信号稳定后
     if testclk='1' and done='1' then
        if std='1' then
           assert dataint =vec2int(r_data)
                           report "read data doesn't match data file!"
                           severity error;
        end if;
        if not endfile(test_file) then
            readline(test_file,buff);
            read(buff,new_br);
            read(buff,new_wr);
            read(buff,addrint);
            read(buff,dataint);
            br<=new_br;
            wr<=new_wr;
            address<=int2vec(addrint,32);
            
            if new_wr='1' and new_br='1' then
               --写操作
               w_data<=int2vec(dataint,32);
            else 
               --读操作
               w_data<=(others=>'0');
			end if;
        end if;
      end if;
  end process read_test_file;
end test1;