diff --git a/ocs/ocs_reg_write_test.py b/ocs/ocs_reg_write_test.py
new file mode 100644
index 0000000..5f5c2c1
--- /dev/null
+++ b/ocs/ocs_reg_write_test.py
@@ -0,0 +1,21 @@
+from utilities import *
+from wr_exp import *
+import argparse
+
+def test_write(exp, argv):
+
+    val = 128
+    for _ in range(10):
+        for ocs in exp.get_cmis():
+            for lane in range(8):
+                ocs.write_reg_b(0, 0xc5, 0xa1 + lane * 2, val)
+                val = 127 if val == 128 else 128
+
+
+if __name__ == '__main__':
+    parser_ = lt_arg_parser(__file__, host=ArgFeat.LIST, port=ArgFeat.LIST, ocs=ArgFeat.NONE)
+    args_ = parser_.parse()
+    print(f'{args_}')
+
+    recursive_per_exp(args_, test_write)
+    log.inf('DONE')