竖条显示
process(hcnt,vcnt)
begin
if hcnt>=143 and hcnt<=223 then GRB<="000";
elsif hcnt>223 and hcnt<=303 then GRB<="001";
elsif hcnt>303 and hcnt<=383 then GRB<="010";
elsif hcnt>383 and hcnt<=463 then GRB<="011";
elsif hcnt>463 and hcnt<=543 then GRB<="100";
elsif hcnt>543 and hcnt<=623 then GRB<="101";
elsif hcnt>623 and hcnt<=703 then GRB<="110";
elsif hcnt>703 and hcnt<=783 then GRB<="111";
end if;
end process;
