diff --git a/sync_rtl/top/TB/xsim_run.tcl b/sync_rtl/top/TB/xsim_run.tcl
new file mode 100644
index 0000000..feade0e
--- /dev/null
+++ b/sync_rtl/top/TB/xsim_run.tcl
@@ -0,0 +1,45 @@
+# xsim_run.tcl - Vivado XSIM for mlkem_top ML-KEM-512 KeyGen.
+#
+# Compiles the full KeyGen datapath + all leaf modules, then runs the
+# end-to-end NIST KAT testbench for count=0..4 (each verifies ek==KAT.pk
+# 800B and dk==KAT.sk 1632B byte-exact).
+#
+# Run from project root:
+#   ./run_tb.sh top
+#   (or: vivado-style step-by-step with the commands below)
+
+# ================================================================
+# Step 1: Compile RTL sources (leaf modules + top)
+# ================================================================
+xvlog -sv --relax -i . sync_rtl/sha3/keccak_round.v
+xvlog -sv --relax -i . sync_rtl/sha3/keccak_core.v
+xvlog -sv --relax -i . sync_rtl/sha3/sha3_top.v
+xvlog -sv --relax -i . sync_rtl/sample_ntt/sample_ntt_sync.v
+xvlog -sv --relax -i . sync_rtl/sample_cbd/sample_cbd_sync.v
+xvlog -sv --relax -i . sync_rtl/ntt/barrett_mul.v
+xvlog -sv --relax -i . sync_rtl/ntt/zeta_rom.v
+xvlog -sv --relax -i . sync_rtl/ntt/butterfly_unit.v
+xvlog -sv --relax -i . sync_rtl/ntt/ntt_core.v
+xvlog -sv --relax -i . sync_rtl/poly_mul/basecase_mul.v
+xvlog -sv --relax -i . sync_rtl/poly_mul/poly_mul_zeta_rom.v
+xvlog -sv --relax -i . sync_rtl/poly_mul/poly_mul_sync.v
+xvlog -sv --relax -i . sync_rtl/top/mlkem_top.v
+
+# ================================================================
+# Step 2: Compile KAT testbench (parameterized by +CASE=n)
+# ================================================================
+xvlog -sv --relax sync_rtl/top/TB/tb_mlkem_kg_katN_xsim.v
+
+# ================================================================
+# Step 3: Elaborate snapshot
+# ================================================================
+xelab tb_mlkem_kg_katN_xsim -s mlkem_kg_kat --timescale 1ns/1ps
+
+# ================================================================
+# Step 4: Run all 5 KAT cases (count=0..4)
+# ================================================================
+xsim mlkem_kg_kat -R -testplusarg CASE=0
+xsim mlkem_kg_kat -R -testplusarg CASE=1
+xsim mlkem_kg_kat -R -testplusarg CASE=2
+xsim mlkem_kg_kat -R -testplusarg CASE=3
+xsim mlkem_kg_kat -R -testplusarg CASE=4