LIBRARY ieee;
USE ieee.std_logic_1164.ALL;
use ieee.std_logic_unsigned.all;
USE ieee.numeric_std.ALL;
USE IEEE.STD_LOGIC_TEXTIO.ALL;
USE STD.TEXTIO.ALL;
entity theswings is
end theswings;
architecture Behavioral of theswings is
signal a_signal_p: std_logic_vector(3 downto 0) := "0000";
signal the_other: std_logic_vector(3 downto 0) := "0000";
file da_goods: TEXT open read_mode is "C:\Users\~~~~\playground\goods";
procedure read_slv(file F: text; value: inout std_logic_vector) is
-- no error checking of any sort is performed by this function
-- it assumes the file is a newline-separated list of strings
-- describing one std_logic_vector each
-- if EOF, then return "XXXXXXXX"
variable tmp: line;
variable tmpr: std_logic_vector(3 downto 0) := "1010";
begin
if endfile(F) then
for i in tmpr'range loop
tmpr(i) := 'X';
end loop;
else
readline(F, tmp);
read(tmp, tmpr);
end if;
end read_slv;
begin
process
--variable invar, outvar: std_logic_vector(3 downto 0);
--variable tmp: line;
variable tmpr: std_logic_vector(3 downto 0);
--variable str: string;
begin
wait for 50 ns;
-- while not endfile(da_goods) loop
-- readline(da_goods, tmp);
-- read(tmp, tmpr);
-- a_signal_p <= tmpr;
-- --a_signal_p <= invar;
-- the_other <= not tmpr;
-- --outvar := the_other;
-- --write(da_bads, the_other);
-- wait for 10 ns;
-- end loop;
for i in 0 to 8 loop
read_slv(da_goods, tmpr);
a_signal_p <= tmpr;
the_other <= not tmpr;
wait for 10 ns;
end loop;
wait;
end process;
END;
正如您可能猜到的那样，注释掉的主循环工作正常，而使用该过程的 for 循环不起作用。（具体来说，在 50 ns 的零之后，所有信号都转到“UUUU”，而不是程序主体可能期望的“1010”。
有人认出我犯的错误吗？我 98% 确定这是一个非常愚蠢的问题，像我这样的菜鸟还无法理解。