common: Add levels parameter to DUMP

This adds a levels parameter to DUMP, allowing dumping just the
top-level signals, instead of the whole hierarchy. This is helpful for
post-synthesis simulation, where all sub-modules are primitives (with
their inputs and outputs already available at the top level).

Signed-off-by: Sean Anderson <seanga2@gmail.com>

rtl/common.vh

@@ -7,14 +7,14 @@
 `define COMMON_VH
 
 `ifdef SYNTHESIS
-`define DUMP
+`define DUMP(levels)
 `else
-`define DUMP \
+`define DUMP(levels) \
 	reg [4096:0] vcdfile; \
 	initial begin \
 		if ($value$plusargs("vcd=%s", vcdfile)) begin \
 			$dumpfile(vcdfile); \
-			$dumpvars; \
+			$dumpvars(levels); \
 		end \
 	end
 `endif

rtl/pcs.v

@@ -92,7 +92,7 @@ module pcs (
 	assign col = transmitting && receiving;
 	assign crs = transmitting || receiving;
 
-	`DUMP
+	`DUMP(0)
 
 endmodule
 

rtl/pmd.v

@@ -225,6 +225,6 @@ module pmd (
 	end
 `endif
 
-	`DUMP
+	`DUMP(0)
 
 endmodule