diff --git a/model/py/message_build.py b/model/py/message_build.py
index 2f4a35cdfb1223db2fa538b8b2ce8082a740ecfb..427215c21b18ebfb63280b90b7300f8dbf6b9d82 100644
--- a/model/py/message_build.py
+++ b/model/py/message_build.py
@@ -18,7 +18,7 @@ def main():
         quit()
     # Read in Descriptor File
     # - contains number of packets of data to generate and random seed
-    stim_file = os.environ["SHA_2_ACC_DIR"] + "/simulate/stimulus/" + "model_builder_stim.csv"
+    stim_file = os.environ["SHA_2_ACC_DIR"] + "/simulate/stimulus/model/" + "model_builder_stim.csv"
     with open(stim_file, "r") as stim:
         csvreader = csv.reader(stim, delimiter=",")
         stim_list = list(csvreader)
@@ -81,21 +81,21 @@ def main():
 
     # Write out Input Data Stimulus to Text File
     input_header = ["input_data", "input_data_last"]
-    with open(os.environ["SHA_2_ACC_DIR"] + "/simulate/stimulus/" + "input_data_builder_stim.csv", "w", encoding="UTF8", newline='') as f:
+    with open(os.environ["SHA_2_ACC_DIR"] + "/simulate/stimulus/testbench/" + "input_data_builder_stim.csv", "w", encoding="UTF8", newline='') as f:
         writer = csv.writer(f)
         for idx, word in enumerate(in_data_words_list):
             writer.writerow(["{0:x}".format(int(word, 2)), in_data_words_last_list[idx]])
             
     # Write out Cfg Stimulus to Text File
     input_header = ["input_cfg_size", "input_cfg_scheme", "input_cfg_last"]
-    with open(os.environ["SHA_2_ACC_DIR"] + "/simulate/stimulus/" + "input_cfg_builder_stim.csv", "w", encoding="UTF8", newline='') as f:
+    with open(os.environ["SHA_2_ACC_DIR"] + "/simulate/stimulus/testbench/" + "input_cfg_builder_stim.csv", "w", encoding="UTF8", newline='') as f:
         writer = csv.writer(f)
         for idx, word in enumerate(cfg_words_list):
             writer.writerow(["{0:x}".format(int(word, 2)), "0", "1"])
             
     # Write out Expected output to text file
     output_header = ["output_data", "output_data_last"]
-    with open(os.environ["SHA_2_ACC_DIR"] + "/simulate/stimulus/" + "output_data_builder_stim.csv", "w", encoding="UTF8", newline='') as f:
+    with open(os.environ["SHA_2_ACC_DIR"] + "/simulate/stimulus/testbench/" + "output_data_builder_stim.csv", "w", encoding="UTF8", newline='') as f:
         writer = csv.writer(f)
         for idx, word in enumerate(out_data_words_list):
             writer.writerow(["{0:x}".format(int(word, 2)), out_data_words_last_list[idx]])
diff --git a/simulate/stimulus/README.md b/simulate/stimulus/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..0215fcf496b4b86b9a1d9a0e46e882d357b8d344
--- /dev/null
+++ b/simulate/stimulus/README.md
@@ -0,0 +1,7 @@
+The csv files in this directory are used for verifcation of systemverilog modules.
+
+The model directory contains a hand written stimulus to be used by python models to generate the testbench stimulus. 
+The first value is the random seed followed by the number of packets:
+    seed,packets
+    
+The testbench directory contains stimulus for the SV testbenches. Input stimulus is fed into the testbench to drive the design and the output is used to verify the outputs of the design.
\ No newline at end of file
diff --git a/simulate/stimulus/model_builder_stim.csv b/simulate/stimulus/model/model_builder_stim.csv
similarity index 100%
rename from simulate/stimulus/model_builder_stim.csv
rename to simulate/stimulus/model/model_builder_stim.csv
diff --git a/simulate/stimulus/input_cfg_builder_stim.csv b/simulate/stimulus/testbench/input_cfg_builder_stim.csv
similarity index 100%
rename from simulate/stimulus/input_cfg_builder_stim.csv
rename to simulate/stimulus/testbench/input_cfg_builder_stim.csv
diff --git a/simulate/stimulus/input_data_builder_stim.csv b/simulate/stimulus/testbench/input_data_builder_stim.csv
similarity index 100%
rename from simulate/stimulus/input_data_builder_stim.csv
rename to simulate/stimulus/testbench/input_data_builder_stim.csv
diff --git a/simulate/stimulus/output_data_builder_stim.csv b/simulate/stimulus/testbench/output_data_builder_stim.csv
similarity index 100%
rename from simulate/stimulus/output_data_builder_stim.csv
rename to simulate/stimulus/testbench/output_data_builder_stim.csv