diff --git a/common.mk b/common.mk
index abb148fc..d055f784 100644
--- a/common.mk
+++ b/common.mk
@@ -257,7 +257,7 @@ $(output_dir)/%.out: $(output_dir)/% $(SIM_PREREQ)
 #########################################################################################
 # include build/project specific makefrags made from the generator
 #########################################################################################
-ifneq ($(filter run% %.run %.out %.vpd %.vcd,$(MAKECMDGOALS)),)
+ifneq ($(filter run% %.run %.out %.vpd %.vcd %.fsdb,$(MAKECMDGOALS)),)
 -include $(build_dir)/$(long_name).d
 endif
 
diff --git a/sims/vcs/Makefile b/sims/vcs/Makefile
index e364830b..550be3c2 100644
--- a/sims/vcs/Makefile
+++ b/sims/vcs/Makefile
@@ -74,15 +74,20 @@ $(sim): $(sim_vsrcs) $(sim_common_files) $(dramsim_lib) $(EXTRA_SIM_REQS)
 $(sim_debug): $(sim_vsrcs) $(sim_common_files) $(dramsim_lib) $(EXTRA_SIM_REQS)
 	rm -rf $(model_dir_debug)
 	$(VCS) $(VCS_OPTS) $(EXTRA_SIM_SOURCES) -o $@ -Mdir=$(model_dir_debug)  \
-	+define+DEBUG
+	+define+DEBUG -debug_access+all -kdb -lca
 
 #########################################################################################
-# create a vcs vpd rule
+# create vcs vpd/fsdb rules
 #########################################################################################
 .PRECIOUS: $(output_dir)/%.vpd %.vpd
 $(output_dir)/%.vpd: $(output_dir)/% $(sim_debug)
 	(set -o pipefail && $(sim_debug) $(PERMISSIVE_ON) $(SIM_FLAGS) $(EXTRA_SIM_FLAGS) $(SEED_FLAG) $(VERBOSE_FLAGS) +vcdplusfile=$@ $(PERMISSIVE_OFF) $< </dev/null 2> >(spike-dasm > $<.out) | tee $<.log)
 
+.PRECIOUS: $(output_dir)/%.fsdb %.fsdb
+$(output_dir)/%.fsdb: $(output_dir)/% $(sim_debug)
+	(set -o pipefail && $(sim_debug) $(PERMISSIVE_ON) $(SIM_FLAGS) $(EXTRA_SIM_FLAGS) $(SEED_FLAG) $(VERBOSE_FLAGS) +fsdbfile=$@ $(PERMISSIVE_OFF) $< </dev/null 2> >(spike-dasm > $<.out) | tee $<.log)
+
+
 #########################################################################################
 # general cleanup rules
 #########################################################################################
diff --git a/vcs.mk b/vcs.mk
index e62b3f07..2a88d39b 100644
--- a/vcs.mk
+++ b/vcs.mk
@@ -1,4 +1,14 @@
+HELP_COMPILATION_VARIABLES += \
+"   USE_FSDB               = set to '1' to build VCS simulator to emit FSDB instead of VPD."
+
+HELP_SIMULATION_VARIABLES += \
+"   USE_FSDB               = set to '1' to run VCS simulator emitting FSDB instead of VPD."
+
+ifdef USE_FSDB
+WAVEFORM_FLAG=+fsdbfile=$(sim_out_name).fsdb
+else
 WAVEFORM_FLAG=+vcdplusfile=$(sim_out_name).vpd
+endif
 
 # If ntb_random_seed unspecified, vcs uses 1 as constant seed.
 # Set ntb_random_seed_automatic to actually get a random seed
@@ -55,3 +65,7 @@ PREPROC_DEFINES = \
 	+define+RANDOMIZE_REG_INIT \
 	+define+RANDOMIZE_GARBAGE_ASSIGN \
 	+define+RANDOMIZE_INVALID_ASSIGN
+
+ifdef USE_FSDB
+PREPROC_DEFINES += +define+FSDB
+endif