大家好，最近编写了一个程序。在试验版的led点阵屏上一次显示字符。我是先把每个要显示的字符设为常量，当时钟信号clk8(8HZ)第16个周期上升沿时，开始输出下一个字符。（先设矢量q,对q计数，16后清零）当时钟clk2(2MHZ)上升沿时，行信号row 加一，开始扫下一行，同时输出对应字符的第row行。 程序如下：library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL; entity xianshi is
port(
clk8,clk2:in std_logic;
row:buffer std_logic_vector(2 downto 0);
line ut std_logic_vector(7 downto 0));
end xianshi; architecture Behavioral of xianshi is
signal q:std_logic_vector(6 downto 0);
signal qq:std_logic_vector(2 downto 0);
type romtable is array (0 to 7) of std_logic_vector (7 downto 0);
constant word0:romtable:=romtable'(
"11111111", --word0~word6定义为常量，是二维数组，每次输出一行
"10000001", --
"10000001", --
"11111111",
"10000000",
"10000000",
"10000000",
"10000000");
constant word1:romtable:=romtable'(
"10000000",
"10000000",
"10000000",
"10000000",
"10000000",
"10000000",
"10000000",
"11111111");
constant word2:romtable:=romtable'(
"11110000",
"10001000",
"10000100",
"10000010",
"10000010",
"10000100",
"10001000",
"11110000");
constant word3:romtable:=romtable'(
"11101111",
"00000001",
"01101101",
"00000001",
"01101101",
"00000001",
"11101111",
"11100001");
constant word4:romtable:=romtable'(
"00000000",
"11111101",
"11111011",
"00000000",
"11110111",
"11110111",
"11110111",
"11100111");
constant word5:romtable:=romtable'(
"01000100",
"01000100",
"01001111",
"11111111",
"01100110",
"01000110",
"11001001",
"01010001");
constant word6:romtable:=romtable'(
"00010100",
"00010010",
"00010001",
"11111111",
"00111000",
"01010100",
"10010010",
"10010001"); begin
qq<=q(6)&q(5)&q(4);
p1:process(clk8,qq)
begin
if(qq<=6) then
if rising_edge(clk8) then
q<=q+'1';
end if;
else q<="0000000";
end if;
end process p1;
p2:process (clk2)
begin
if rising_edge(clk2) then
row<=row+'1';
end if;
end process p2;
p3:process (row,qq)
begin
if (qq=0) then
line<=word0(conv_integer (row));
elsif (qq=1) then
line<=word1(conv_integer(row));
elsif (qq=2) then
line<=word2(conv_integer(row));
elsif(qq=3) then
line<=word3(conv_integer(row));
elsif (qq=4) then
line<=word4(conv_integer(row));
elsif (qq=5) then
line<=word5(conv_integer(row));
else
line<=word6(conv_integer(row));
end if;
end process p3; end Behavioral;
此程序在仿真时，row 信号是红颜色，大小是xxx，为不定态，为什么，哪个地方出错了？ 冥思苦想好久，也找不到答案，请各位赐教，万分感谢 | 
