In reply to philerpeng:
I don’t think you can use like that in verilog.
Please try:
// Module A
module A #(parameter NUM_SLAVES = 1) (
input [NUM_SLAVES-1:0] sig_a
);
endmodule
// Module B
module B (
output sig_b
);
endmodule
// Module C
module C ();
wire sig;
B inst_b(.sig_b(sig));
A #(1) inst_A (.sig_a (sig));
endmodule