diff --git a/Bender.yml b/Bender.yml
index 97468f09..41bafeff 100644
--- a/Bender.yml
+++ b/Bender.yml
@@ -35,7 +35,7 @@ sources:
   # add your design files containing anything but modules (packages) here
 
     # RTL
-  - target: not(netlist_yosys)
+  - target: not(any(netlist_yosys, netlist_openroad))
     files:
       # Level 1
       - rtl/core_wrap.sv
@@ -49,16 +49,21 @@ sources:
       # Level 3
       - rtl/croc_soc.sv
 
-  - target: not(fpga)
+  - target: not(any(fpga, netlist_yosys, netlist_openroad))
     files:
       # Level 0
       - rtl/croc_chip.sv
   
-  # netlist for simulation
+  # yosys netlist for simulation
   - target: netlist_yosys
     files:
       - yosys/out/croc_chip_yosys_debug.v
 
+  # openroad netlist for simulation
+  - target: netlist_openroad
+    files:
+      - openroad/out/croc.v
+
   - target: any(simulation, verilator)
     files:
       - rtl/tb_croc_soc.sv
@@ -187,4 +192,4 @@ vendor_package:
       - { from: 'rtl/',                                         to: '',                      patch_dir: 'rtl/' }
       - { from: 'README.md',                                    to: 'README.md',             patch_dir: '' }
       - { from: 'doc/03_reference/images/blockdiagram.svg',     to: 'blockdiagram.svg',      patch_dir: '' }
-      - { from: 'vendor/lowrisc_ip/ip/prim/rtl/',               to: 'include/lowrisc_prim/', patch_dir: 'lowrisc_prim/' }
\ No newline at end of file
+      - { from: 'vendor/lowrisc_ip/ip/prim/rtl/',               to: 'include/lowrisc_prim/', patch_dir: 'lowrisc_prim/' }
diff --git a/Makefile b/Makefile
index 1d092128..51d562d7 100644
--- a/Makefile
+++ b/Makefile
@@ -13,6 +13,8 @@ YOSYS     ?= yosys
 OPENROAD  ?= openroad
 KLAYOUT   ?= klayout
 VSIM      ?= vsim
+VLOGAN    ?= vlogan
+VCS	      ?= vcs
 REGGEN    ?= $(PYTHON3) $(shell $(BENDER) path register_interface)/vendor/lowrisc_opentitan/util/regtool.py
 
 # Directories
@@ -108,7 +110,46 @@ verilator/obj_dir/Vtb_croc_soc: verilator/croc.f $(SW_HEX)
 verilator: verilator/obj_dir/Vtb_croc_soc
 	cd verilator; obj_dir/Vtb_croc_soc +binary="$(realpath $(SW_HEX))"
 
-.PHONY: verilator vsim vsim-yosys
+# VCS
+VCS_SCRIPT_ARGS = -assert svaext +v2k -kdb -override_timescale=1ns/10ps -debug_access+all
+VCS_COMPILE_ARGS = -kdb -lca -sverilog -full64 -j8 -l compile.log +vcs+fsdbon -debug_access+all +lint=TFIPC-L +lint=PCWM +warn=noCWUC +warn=noUII-L -override_timescale=1ns/10ps
+vcs/compile_rtl.sh: Bender.lock Bender.yml
+	$(BENDER) script vcs -t rtl -t vcs -t simulation -t verilator -DSYNTHESIS -DSIMULATION --vlog-arg="$(VCS_SCRIPT_ARGS)" --vlogan-bin="$(VLOGAN)" > $@
+	chmod +x $@
+
+vcs/compile_netlist_yosys.sh: Bender.lock Bender.yml
+	$(BENDER) script vcs -t ihp13 -t vcs -t simulation -t verilator -t netlist_yosys -DSYNTHESIS -DSIMULATION --vlog-arg="$(VCS_SCRIPT_ARGS)" --vlogan-bin="$(VLOGAN)" > $@
+	cat vcs/compile_tech.sh >> $@
+	chmod +x $@
+
+vcs/compile_netlist_openroad.sh: Bender.lock Bender.yml
+	$(BENDER) script vcs -t ihp13 -t vcs -t simulation -t verilator -t netlist_openroad -DSYNTHESIS -DSIMULATION --vlog-arg="$(VCS_SCRIPT_ARGS)" --vlogan-bin="$(VLOGAN)" > $@
+	cat vcs/compile_tech.sh >> $@
+	chmod +x $@
+
+vcs/tb_croc_soc.sim: vcs/compile_rtl.sh
+	cd vcs; ./compile_rtl.sh
+	cd vcs; $(VCS) $(VCS_COMPILE_ARGS) -o tb_croc_soc.sim tb_croc_soc
+
+vcs/tb_croc_soc_yosys.sim: vcs/compile_netlist_yosys.sh yosys/out/croc_chip_yosys_debug.v
+	cd vcs; ./compile_netlist_yosys.sh
+	cd vcs; $(VCS) $(VCS_COMPILE_ARGS) -o tb_croc_soc_yosys.sim tb_croc_soc
+
+vcs/tb_croc_soc_openroad.sim: vcs/compile_netlist_openroad.sh openroad/out/croc.v
+	cd vcs; ./compile_netlist_openroad.sh
+	cd vcs; $(VCS) $(VCS_COMPILE_ARGS) -o tb_croc_soc_openroad.sim tb_croc_soc
+
+## Simulate RTL using VCS
+vcs: vcs/tb_croc_soc.sim $(SW_HEX)
+	cd vcs; ./tb_croc_soc.sim +fsdb+all=on +binary="$(realpath $(SW_HEX))" -l transcript.log
+
+vcs-yosys: vcs/tb_croc_soc_yosys.sim $(SW_HEX)
+	cd vcs; ./tb_croc_soc_yosys.sim +fsdb+all=on +binary="$(realpath $(SW_HEX))" -l transcript.log
+
+vcs-openroad: vcs/tb_croc_soc_openroad.sim $(SW_HEX)
+	cd vcs; ./tb_croc_soc_openroad.sim +fsdb+all=on +binary="$(realpath $(SW_HEX))" -l transcript.log
+
+.PHONY: verilator vsim vsim-yosys vcs vcs-yosys vcs-openroad
 
 
 ####################
diff --git a/README.md b/README.md
index 61104a8a..6b945ece 100644
--- a/README.md
+++ b/README.md
@@ -175,6 +175,10 @@ If you have Questasim/Modelsim, you can also run:
 make vsim
 ```
 
+If you have VCS, you can also run:
+```sh
+make vcs
+```
 
 The most important make targets are documented, you can list them with:
 ```sh
diff --git a/rtl/tb_croc_soc.sv b/rtl/tb_croc_soc.sv
index 71782388..479f13c6 100644
--- a/rtl/tb_croc_soc.sv
+++ b/rtl/tb_croc_soc.sv
@@ -377,7 +377,7 @@ module tb_croc_soc #(
                  if (uart_read_buf.size() > 0) begin
                     automatic string uart_str = "";               
                     foreach (uart_read_buf[i]) begin
-                        uart_str = {uart_str, uart_read_buf[i]};
+                        uart_str = {uart_str, string'(uart_read_buf[i])};
                     end
                     
                     $display("@%t | [UART] %s", $time, uart_str);
diff --git a/rtl/user_pkg.sv b/rtl/user_pkg.sv
index 8d8d10f1..a59f3461 100644
--- a/rtl/user_pkg.sv
+++ b/rtl/user_pkg.sv
@@ -26,7 +26,7 @@ package user_pkg;
   localparam bit [31:0] UserRomAddrOffset   = croc_pkg::UserBaseAddr; // 32'h2000_0000;
   localparam bit [31:0] UserRomAddrRange    = 32'h0000_1000;          // every subordinate has at least 4KB
 
-  localparam int unsigned NumDemuxSbrRules  = NumUserDomainSubordinates; // number of address rules in the decoder
+  localparam int unsigned NumDemuxSbrRules  = NumUserDomainSubordinates > 0 ? NumUserDomainSubordinates : 1; // number of address rules in the decoder
   localparam int unsigned NumDemuxSbr       = NumDemuxSbrRules + 1; // additional OBI error, used for signal arrays
 
   // Enum for bus indices
diff --git a/vcs/.gitignore b/vcs/.gitignore
new file mode 100644
index 00000000..ded2ecc6
--- /dev/null
+++ b/vcs/.gitignore
@@ -0,0 +1,12 @@
+AN.DB
+work.lib++
+tb_croc_soc*
+vc_hdrs.h
+csrc
+ucli.key
+croc.fst
+compile_rtl.sh
+compile_netlist*
+compile.log
+novas*
+transcript.log
diff --git a/vcs/compile_tech.sh b/vcs/compile_tech.sh
new file mode 100755
index 00000000..7f50a04a
--- /dev/null
+++ b/vcs/compile_tech.sh
@@ -0,0 +1,14 @@
+$VLOGAN -sverilog \
+    -full64 \
+    -assert svaext +v2k -kdb -override_timescale=1ns/10ps -debug_access+all \
+    "+define+FUNCTIONAL" \
+    "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_stdcell/verilog/sg13g2_stdcell.v" \
+    "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_core_behavioral_bm_bist.v" \
+    "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_64x64_c2_bm_bist.v" \
+    "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_256x64_c2_bm_bist.v" \
+    "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_512x64_c2_bm_bist.v" \
+    "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_1024x64_c2_bm_bist.v" \
+    "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_2048x64_c2_bm_bist.v" \
+    "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_256x48_c2_bm_bist.v" \
+    "$ROOT/ihp13/tc_sram_impl.sv" \
+    "$ROOT/ihp13/tc_clk.sv"
diff --git a/vsim/compile_tech.tcl b/vsim/compile_tech.tcl
index 01e865b3..0ab1a270 100644
--- a/vsim/compile_tech.tcl
+++ b/vsim/compile_tech.tcl
@@ -15,7 +15,6 @@ if {[catch { vlog -incr -sv \
     "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_1024x64_c2_bm_bist.v" \
     "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_2048x64_c2_bm_bist.v" \
     "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_256x48_c2_bm_bist.v" \
-    "$ROOT/ihp13/pdk/ihp-sg13g2/libs.ref/sg13g2_sram/verilog/RM_IHPSG13_1P_256x48_c2_bm_bist.v" \
-    "$ROOT/ihp13/tc_sram.sv" \
-    "$ROOT/ihp13/tc_clk.s_implv" \
+    "$ROOT/ihp13/tc_sram_impl.sv" \
+    "$ROOT/ihp13/tc_clk.sv" \
 }]} {return 1}