标题: 求助：一个xilinx警告，请大家指点下！！ [打印本页] 作者: zhry 时间: 2009-4-3 15:41 标题: 求助：一个xilinx警告，请大家指点下！！ 小弟刚用ise，综合时产生了一个警告，不太明白，希望高手能指点下，多谢了！！ . _$ t ` T& T; a( G" I# QWARNING:Xst:2183 - Unit actel: the following tristate(s) are NOT replaced by logic (Please refer to Answer Record 20048 for more information): D<0>_MLTSRCEDGE, D<1>_MLTSRCEDGE, D<2>_MLTSRCEDGE, D<3>_MLTSRCEDGE, D<4>_MLTSRCEDGE, D<5>_MLTSRCEDGE, D<7>_MLTSRCEDGE.作者: oxygen 时间: 2009-4-4 08:36
看看你的设计属于下面的哪种情况？ - V) R" l- M% u9 f! V$ N- The tristate is connected to a black box. # r) b& ~+ D4 i/ \2 k: D& I- The tristate is connected to the output of a block, and the hierarchy of the block is preserved. : ^2 n1 N2 y% P; u: \2 Y+ X/ p- The tristate is connected to a top-level output. 7 d' a, W6 a7 ^; g/ |
- The "tristate2logic" constraint is set to "no" on the block where tristates are placed or on the signals to which tristates are connected.作者: zhry 时间: 2009-4-7 09:52 版主您好！非常感谢您的回复!5 z! t! F; ~2 E1 T0 c% p3 \1 N
您说的这段我也看到过，但是看不太明白。数据线D ：inout std_logic_vector(7 downto 0),类型为inout数据输出的程序：9 x: D3 ?' S1 p5 o) h. F. Z% h# R
process(NCS2 ,NCS1,A19,A18,A3,A2,A1,WR,D) * o* j! F$ L! b& B& Y begin x! w. A) ]( }8 T if(not NCS2 and NCS1 and not A19 and A18 and not A3 and not A2 and not A1 and not WR) = '1' then 6 U, ^/ J' S% P# x2 P1 c" U! p a(0)<=not D(0);$ e [' W" u# R3 i2 b9 Q
a(1)<=not D(1);9 a) @8 I, T U- Y# `1 M& F6 Z; S
a(2)<=not D(2); 1 B! {5 ]4 Z4 n) L2 E$ ~ end if; / j( K& d" b0 U/ g9 _$ y ledg<= a(0); - d& `& G" s5 _( I ledy<= a(1); 5 ] ^7 E. g. s1 ^8 I8 w ledr<= a(2); " `/ n/ S5 _" T4 j+ n end process;, G, B6 a9 Q) U8 s4 _$ h* o4 q0 a, z
数据读入的程序：0 k( L2 a' {5 H+ P9 n% W
D(7)<= not oct when(not NCS2 and NCS1 and not A19 and A18 and not A3 and not A2 and not A1 and not RD) = '1' else 'Z'; . v3 D: t; e# H0 X D(5)<=keyval(0) when (not NCS2 and NCS1 and not A19 and A18 and not A3 and A2 and A1 and not RD)='1' else 'Z';7 j7 g5 o% F3 { P& ^
D(4)<=keyval(1) when (not NCS2 and NCS1 and not A19 and A18 and not A3 and A2 and A1 and not RD)='1' else 'Z';- b9 C7 \- ~! P$ b) Y) x0 U, D
D(3)<=keyval(2) when (not NCS2 and NCS1 and not A19 and A18 and not A3 and A2 and A1 and not RD)='1' else 'Z';0 A* [% Z- `& U. Q& M0 p9 |/ w
D(2)<=keyval(3) when (not NCS2 and NCS1 and not A19 and A18 and not A3 and A2 and A1 and not RD)='1' else 'Z'; 9 T6 _3 j% n$ ?% S" g9 b' c D(1)<=keyval(4) when (not NCS2 and NCS1 and not A19 and A18 and not A3 and A2 and A1 and not RD)='1' else 'Z'; # i" ^& e \$ f: S& J9 eD(0)<=keyval(5) when (not NCS2 and NCS1 and not A19 and A18 and not A3 and A2 and A1 and not RD)='1' else 'Z';* q* E& q! z! E" _; a 就是这里出的问题，我把数据读入的程序注释掉，这个警告就没了！请问这是什么原因呢？作者: oxygen 时间: 2009-4-7 21:45
好长的组合逻辑。。如果可以请改为同步设计。。