3 files changed, 12 insertions, 4 deletions
diff --git a/.gitignore b/.gitignore
index 310a92b..0166bb2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,3 +11,6 @@ greybox_tmp/
 *.done
 *.bak
 *.qws
+
+# ignores for the makefile build system
+waves/
diff --git a/Makefile b/Makefile
index 55be36b..d97f6a0 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,8 @@ IVFLAGS   := -g2005-sv
 
 SIM_SRCS  := $(wildcard *_tb.v)
 SIMS      := $(SIM_SRCS:.v=.sim)
-WAVES     := $(SIM_SRCS:.v=.vcd)
+WAVES     := $(addprefix waves/,$(SIM_SRCS:.v=.vcd))
+DIRS      := waves
 
 DEPS                = $(sort $(1) $(foreach d,$(1),$(DEPS-$(d))))
 DEPS-alu           := $(call DEPS,shifter)
@@ -17,9 +18,13 @@ all: simulate
 simulate: $(WAVES)
 
 clean:
-	rm -f $(SIMS) $(WAVES)
+	rm -f $(SIMS)
+	rm -rf $(DIRS)
 
-%.vcd: %.sim
+$(DIRS):
+	mkdir -p $@
+
+waves/%.vcd: %.sim | waves
 	vvp $<
 
 .SECONDEXPANSION:
diff --git a/testbench.vh b/testbench.vh
index c60f66d..565daaa 100644
--- a/testbench.vh
+++ b/testbench.vh
@@ -7,7 +7,7 @@
 `define STRINGIFY(x) `"x`"
 
 `define DUMPWAVE(m) \
-	$dumpfile({`STRINGIFY(m), ".vcd"}); \
+	$dumpfile({"waves/", `STRINGIFY(m), ".vcd"}); \
 	$dumpvars(0, m);
 
 task skip_comments(input integer file);