在ISE12.4版本中，用ISE自带的综合工具XST综合时出现以下错误：ERROR:Xst:902 - "nc_calculate.v" line 82: Unexpected left_nzc event in always block sensitivity list.

源程序：行82 always@(*)k_idx,nzc_valid,block_nzc)begin nT = 0; uT = 0; nL = 0; uL = 0; if(is_luma) begin case(block_idx) 4'h0: begin nT = top_nzc[0]; nL = left_nzc[0]; uT=1; uL=1; end ……..解决办法：1、将always@(*)改为always@(aaa) aaa为begin end块内等号右边的所有变量和begin end块中所有input变量如：always@(is_luma or block_idx or top_nzc[0] or .....)2、将所用器件改为 family:Virtex6 Device:XC6VLX240T。原来为Virtex5。下面来看：always@(*) 指的是对其后面语句块中所有的输入变量的变化时敏感的。Always@(*) 和always@*的区别：Example 1always @(*) // equivalent to @(a or b or c or d or f)y = (a & b) | (c & d) | myfunction(f);Example 2always @* begin // equivalent to @(a or b or c or d or tmp1 or tmp2)tmp1 = a & b;tmp2 = c & d;y = tmp1 | tmp2;endExample 3always @* begin // equivalent to @(b)@(i) kid = b; // i is not added to @*EndExample 4always @* begin // equivalent to @(a or b or c or d)x = a ^ b;@* // equivalent to @(c or d)x = c ^ d;end