才学fpga，很多东西都很迷惑，这个程序写完了，我不知道该如何处理综合后出现的警告，在网上查了一下，因为程序不同，出现同样的警告的原因不一样，希望高手指点一下！十分感谢！

module shift_reg (data_read,rst,data,s_buffer,note);
output reg [95:0] s_buffer;
output note;
input rst;
input [7:0] data;
input data_read;
reg note;
always @(posedge data_read,negedge rst)
begin
if (~rst)
begin
s_buffer<=0;
note<=0;
end
else
begin
s_buffer <= {s_buffer[87:0], data};
note<=1;
end
end
endmodule
出现的警告：
WARNING:Xst:2677 - Node <u3/s_buffer_95> of sequential type is unconnected in block <allall>.
......................................................................................................................................................
WARNING:Xst:2677 - Node <u3/s_buffer_4> of sequential type is unconnected in block <allall>.
WARNING:Xst:2677 - Node <u3/s_buffer_3> of sequential type is unconnected in block <allall>.
WARNING:Xst:2677 - Node <u3/s_buffer_2> of sequential type is unconnected in block <allall>.
WARNING:Xst:2677 - Node <u3/s_buffer_1> of sequential type is unconnected in block <allall>.