小弟写了个反相器,程序:
library ieee;
use ieee.std_logic_1164.all;
entity notbuffer is
port(a : in std_logic;b out std_logic);
end notbuffer;
architecture notbuffer of notbuffer is
begin
if(a'event) then
b<=NOT a AFTER 5 ns;
end if;
end notbuffer;
编译时一直提示if附近有语法错误 请各位大侠帮忙看看,小弟感激不尽! |