diff --git a/ut_backend/ctrl_block/decode/test_rv_decode.py b/ut_backend/ctrl_block/decode/test_rv_decode.py
index eec6d1e..cbf0793 100644
--- a/ut_backend/ctrl_block/decode/test_rv_decode.py
+++ b/ut_backend/ctrl_block/decode/test_rv_decode.py
@@ -10,15 +10,18 @@ from comm import TAG_LONG_TIME_RUN, debug
 from dut.rvcexpander.UT_RVCExpander import *
 
 
-# rvc test
 def rvc_expand(full_inst):
+    """
+    Test the RVC expansion function
+    Parameters:
+        @full_inst: whether to use a full instruction set
+    """
     if full_inst:
         ref_insts  = generate_rvc_instructions()
     else:
         ref_insts  = generate_random_32bits(1)
     rvc_expand = DUTRVCExpander()
     rvc_expand.io_in.AsImmWrite()
-    debug("###################### test_rvc_expand ##########################")
     for insn in ref_insts:
         c_void_ptr = libdisasm.disasm(ctypes.c_uint64(insn))
         insn_disasm = ctypes.cast(c_void_ptr, ctypes.c_char_p).value.decode('utf-8')
@@ -35,18 +38,27 @@ def rvc_expand(full_inst):
 
 
 def test_rvc_expand():
+    """
+    Test the RVC expansion function with a partial instruction set
+    """
     rvc_expand(False)
 
 
 @pytest.mark.toffee_tags(TAG_LONG_TIME_RUN)
 def test_rvc_expand_full():
+    """
+    Test the RVC expansion function with a full instruction set
+    """
     rvc_expand(True)
 
 
-# rvc test, processed by the decoder module
-@pytest.mark.toffee_tags(version="openxiangshan-kmh-97e37a2237-24092702 < openxiangshan-kmh-97e37a2237-24092703")
+@pytest.mark.toffee_tags(version="openxiangshan-kmh-97e37a2237-24092701 < openxiangshan-kmh-97e37a2237-24092703")
 def test_rvc_inst(decoder_fixture):
-    debug("###################### test_rvc_inst ##########################")
+    """
+    Test the RVC instruction set, an example of the tag version in range.
+    Parameters:
+        @decoder_fixture: the fixture of the decoder
+    """
     decoder = decoder_fixture
     need_log_file   = True
     # insn_list_temp  = generate_rvc_instructions()
@@ -56,9 +68,12 @@ def test_rvc_inst(decoder_fixture):
     g.add_cover_point(decoder, {"fast_check_RVC_ramdom": lambda _: True}, name="RVC").sample()
 
 
-# randomly generate instructions for testing
 def test_rvi_inst(decoder_fixture):
-    debug("###################### test_rvi_inst ##########################")
+    """
+    Test the RVI instruction set. randomly generate instructions for testing
+    Parameters:
+        @decoder_fixture: the fixture of the decoder
+    """
     decoder = decoder_fixture
     need_log_file   = True
     insn_list_temp  = generate_random_32bits(100)
@@ -67,9 +82,12 @@ def test_rvi_inst(decoder_fixture):
     g.add_cover_point(decoder, {"fast_check_random_32bit_int": lambda _: True}, name="RVI").sample()
 
 
-# testing of V extension instructions, which are not actually used
 def test_rv_custom_inst(decoder_fixture):
-    debug("###################### test_rv_custom_inst ##########################")
+    """
+    Test the custom instruction set. Testing of V extension instructions, which are not actually used
+    Parameters:
+        @decoder_fixture: the fixture of the decoder
+    """
     decoder = decoder_fixture
     need_log_file   = True
     custom_v_opcode   = 0b1010111