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首先谢谢指点:<br /><br />请大侠看一下下边的代码段:<br /><br />PROCESS(call,call_off,reset_all)<br />begin<br /> if(reset_all='1')then<br /> q1<='1';<br /> q4<='1';<br /> elsif(call='1') then<br /> q4<='1';<br /> q1<='0';<br /> elsif(call_off='1') then<br /> q4<='0' ;<br /> q1<='1';<br />end if;<br />end process ;<br /><br />和<br /><br />PROCESS(call,call_off,reset_all)<br />begin<br /> if(reset_all='1')then<br /> q1<='1';<br /> q4<='1';<br /> elsif(call'event and call='1') then<br /> q4<='1';<br /> q1<='0';<br /> elsif(call_off='1') then<br /> q4<='0' ;<br /> q1<='1';<br />end if;<br />end process ;<br /><br />请问为什么下边的编译不通过,出现下列错误:<br /><br />ERROR:Xst:827 - D:/CPLD/ering.vhdl line 31: Signal q1 cannot be synthesized, bad synchronous description.<br />ERROR: XST failed<br /><br />这两条错误是什么错误啊?<br /><br />请前辈指点,小弟不胜感激,谢谢!!<br /> |
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