<span style="" >module sin(clk,reset,sin_out);
input clk,reset;
output[7:0]sin_out;
reg[7:0]sin_out;
reg[6:0]num;
always@(posedge clk or posedge reset)
begin
if(reset)
sin_out<=0;
else if(num==63)
num<=0;
else
num<=num+1;
case(num)
0:sin_out=255;
1:sin_out=254;
2:sin_out<=252;
3:sin_out<=249;
4:sin_out<=245;
5:sin_out<=239;
6:sin_out<=233;
7:sin_out<=225;
8:sin_out<=217;
9:sin_out<=207;
10:sin_out<=197;
11:sin_out<=186;
12:sin_out<=174;
13:sin_out<=162;
14:sin_out<=150;
15:sin_out<=137;
16:sin_out<=124;
17:sin_out<=112;
18:sin_out<=99;
19:sin_out<=87;
20:sin_out<=75;
21:sin_out<=64;
22:sin_out<=53;
23:sin_out<=43;
24:sin_out<=34;
25:sin_out<=26;
26:sin_out<=19;
27:sin_out<=13;
28:sin_out<=8;
29:sin_out<=4;
30:sin_out<=1;
31:sin_out<=0;
32:sin_out<=0;
33:sin_out<=1;
34:sin_out<=4;
35:sin_out<=8;
36:sin_out<=13;
37:sin_out<=19;
38:sin_out<=26;
39:sin_out<=34;
40:sin_out<=43;
41:sin_out<=53;
42:sin_out<=64;
43:sin_out<=75;
44:sin_out<=87;
45:sin_out<=99;
46:sin_out<=112;
47:sin_out<=124;
48:sin_out<=137;
49:sin_out<=150;
50:sin_out<=162;
51:sin_out<=174;
52:sin_out<=186;
53:sin_out<=197;
54:sin_out<=207;
55:sin_out<=217;
56:sin_out<=225;
57:sin_out<=233;
58:sin_out<=239;
59:sin_out<=245;
60:sin_out<=249;
61:sin_out<=252;
62:sin_out<=254;
63:sin_out<=255;
default:sin_out<=8'bx;
endcase
end
endmodule


运行会报错"sin.v" line 34: The logic for <sin_out> does not match a known FF or Latch template. The description style you are using to describe a register or latch is not supported in the current software release.</div>



各位大神有人知道该怎么修改吗