diff --git a/libsigrokdecode4DSL/decoders/autonegotiation/__init__.py b/libsigrokdecode4DSL/decoders/autonegotiation/__init__.py
new file mode 100755
index 00000000..461c1f65
--- /dev/null
+++ b/libsigrokdecode4DSL/decoders/autonegotiation/__init__.py
@@ -0,0 +1,25 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2021 Quard <2014500726@smail.xtu.edu.cn>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
+##
+
+'''
+The Auto-Negotiation specification includes reception, arbitration,
+and transmission of normal link pulses (NLPs).
+'''
+
+from .pd import Decoder
diff --git a/libsigrokdecode4DSL/decoders/autonegotiation/pd.py b/libsigrokdecode4DSL/decoders/autonegotiation/pd.py
new file mode 100755
index 00000000..20fc595e
--- /dev/null
+++ b/libsigrokdecode4DSL/decoders/autonegotiation/pd.py
@@ -0,0 +1,103 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2021 Quard <2014500726@smail.xtu.edu.cn>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
+##
+
+import sigrokdecode as srd
+
+class Decoder(srd.Decoder):
+    api_version = 3
+    id = 'eth_auto_negotiation'
+    name = 'ETH_AN'
+    longname = 'ETH Auto Negotiation'
+    desc = 'ETH Auto Negotiation protocol.'
+    license = 'gplv2+'
+    inputs = ['logic']
+    outputs = ['eth_an']
+    tags = ['PC']
+    channels = (
+        {'id': 'dp', 'name': 'TX+', 'desc': 'ETH TX+ signal'},
+    )
+    annotations = (
+        ('data', 'FLP data'),
+        ('format', 'format describe'),
+        ('bit', 'Bit'),
+        ('NLP', 'Normal link pulses'),
+    )
+    annotation_rows = (
+        ('data',  'Data', (0,)),
+        ('format',  'Format', (1,)),
+        ('bit', 'Bit', (2,)),
+        ('NLP', 'NLP', (3,)),
+    )
+
+    def __init__(self):
+        self.reset()
+
+    def reset(self):
+        self.ss = self.es = 0
+        self.last_ss = self.last_es = 0
+        self.last_vaild_ss = 0
+        self.samplerate = None
+        self.samplenum = 0
+        self.hex = 0
+
+    def start(self):
+        self.out_python = self.register(srd.OUTPUT_PYTHON)
+        self.out_ann = self.register(srd.OUTPUT_ANN)
+        self.out_binary = self.register(srd.OUTPUT_BINARY)
+
+    def metadata(self, key, value):
+        if key == srd.SRD_CONF_SAMPLERATE:
+            self.samplerate = value
+
+    def decode(self):
+        index = 0
+        data_list = []
+        while True:
+            self.wait({0: 'r'})
+            self.ss = self.samplenum
+            self.wait({0: 'e'})
+            self.es = self.samplenum
+
+            length = float(self.es - self.ss)/self.samplerate
+            if length <= 1.0e-5 and length >= 1.0e-6: # 1us ~ 10us 
+                self.put(self.ss, self.es, self.out_ann, [3, ['NLP']])
+                temp_length = self.ss - self.last_vaild_ss
+                length = float(temp_length)/self.samplerate
+                self.last_vaild_ss = self.ss
+                if length <= 7.0e-5 and length >= 6.0e-5: # 60us ~ 70us
+                    self.put(self.last_ss, self.es, self.out_ann, [2, ['0x1']])
+                    self.hex = self.hex|0x1<<index
+                    data_list.append([self.ss, self.es,self.last_ss,self.last_es])
+                    index = index + 1
+                    self.last_vaild_ss = 0
+                elif length <= 1.4e-4 and length >= 1.2e-4: # 120us ~ 140us
+                    self.put(self.last_ss, self.es-(temp_length>>1), self.out_ann, [2, ['0x0']])
+                    data_list.append([self.ss-(temp_length>>1), self.es-(temp_length>>1),self.last_ss,self.last_es])
+                    index = index + 1
+                self.last_ss = self.ss
+                self.last_es = self.es
+
+            if index == 16:
+                self.put(data_list[0][2], data_list[15][1], self.out_ann, [0, ["Data:"+str(hex(self.hex))]])
+                self.put(data_list[0][2], data_list[4][1], self.out_ann, [1, ["Selector field:"+str(hex(self.hex&0x1f))]])
+                self.put(data_list[5][2], data_list[12][1], self.out_ann, [1, ["Technology ability field:"+str(hex(((self.hex>>5)&0xff)))]])
+                self.put(data_list[13][2], data_list[15][1], self.out_ann, [1, ["Other fields:"+str(hex(((self.hex>>13)&0x7)))]])
+                data_list = []
+                index = 0
+                self.hex = 0
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