标题: 这是什么问题？ [打印本页]
作者: topzyb 时间: 2006-7-26 17:33 标题: 这是什么问题？
Error: Can't resolve multiple constant drivers for net "readyflag1" at SPIControl.vhd(159)
作者: topzyb 时间: 2006-7-26 17:36
-------------------------------------------------------------------
-------------输出LCD控制数据或读取LCD值----------------------------
-------------------------------------------------------------------
process(sck,spincs,dbflag,lcdflag)
begin
if(lcdflag = '1')then
if(spincs'event and spincs = '1')then
reset <= dtemp (13);
e <= dtemp (12);
csa <= dtemp (11);
rw <= dtemp (10);
di <= dtemp (9);
csb <= dtemp (8);
db <= dtemp(7 downto 0);
db<=db; --delay time
db<=db; --delay time
db<=db; --delay time
db<=db; --delay time
dbo <=db; --取回LCD数据
readyflag<='1';
end if;
elsif(dbflag = '1')then
if(spincs'event and spincs = '1')then
reset <= dtemp (13);
e <= dtemp (12);
csa <= dtemp (11);
rw <= dtemp (10);
di <= dtemp (9);
csb <= dtemp (8);
db <= dtemp(7 downto 0);
end if;
end if;
end process;
-------------------------------------------------------------------
-------------返回SPI读取数据---------------------------------------
-------------------------------------------------------------------
process(sck,readyflag)
begin
if (readyflag='1') then
if(sck'event and sck = '0')then
if(count = "0000")then
spiso <= dbo(7);
elsif(count = "0001")then
spiso <= dbo(6);
elsif(count = "0010")then
spiso <= dbo(5);
elsif(count = "0011")then
spiso <= dbo(4);
elsif(count = "0100")then
spiso <= dbo(3);
elsif(count = "0101")then
spiso <= dbo(2);
elsif(count = "0111")then
spiso <= dbo(1);
elsif(count = "1000")then
spiso <= dbo(0);
readyflag<='0';
else
spiso <= '0';
end if;
end if;
end if;
end process;
end behav;
作者: topzyb 时间: 2006-7-26 17:41
我是想用readyflag做为一个标志位，当发出LCD读取命令后，把readyflag=1,而当发送完数据后，把readyflag=0;但在这个程序中出现上面的问题，不知道怎么解决？
作者: bemoon 时间: 2006-7-26 17:53
错误提示的意思是readyflag1这个信号被1个以上的信号驱动了。检查一下程序吧，看看是不是有不同的process影响readyflag1。
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