sipi: Initial version of the SIPI protocol to form a Zipwire stack

2 files changed, 212 insertions, 0 deletions

diff --git a/decoders/sipi/__init__.py b/decoders/sipi/__init__.py
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+++ b/decoders/sipi/__init__.py
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+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2020 Soeren Apel <soeren@apelpie.net>
+##
+## 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 Serial Inter-Processor Interface (SIPI) is a higher-level protocol that runs
+over the LFAST physical interface. Together, they form the NXP ZipWire interface.
+
+The SIPI interface is also provided by Infineon as HSST, using HSCT for transport.
+
+For details see https://www.nxp.com/docs/en/application-note/AN5134.pdf and
+https://hitex.co.uk/fileadmin/uk-files/downloads/ShieldBuddy/tc27xD_um_v2.2.pdf
+'''
+
+from .pd import Decoder
diff --git a/decoders/sipi/pd.py b/decoders/sipi/pd.py
new file mode 100644
index 0000000..73c5eb9
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+++ b/decoders/sipi/pd.py
@@ -0,0 +1,182 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2020 Soeren Apel <soeren@apelpie.net>
+##
+## 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
+from binascii import crc_hqx
+
+# See tc27xD_um_v2.2.pdf, Table 20-2
+# (name, addr byte count, data byte count)
+command_codes = {
+    0b00000: ('Read byte', 4, 0),
+    0b00001: ('Read 2 byte', 4, 0),
+    0b00010: ('Read 4 byte', 4, 0),
+    # Reserved
+    0b00100: ('Write byte with ACK', 4, 4),
+    0b00101: ('Write 2 byte with ACK', 4, 4),
+    0b00110: ('Write 4 byte with ACK', 4, 4),
+    # Reserved
+    0b01000: ('ACK', 0, 0),
+    0b01001: ('NACK (Target Error)', 0, 0),
+    0b01010: ('Read Answer with ACK', 4, 4),
+    # Reserved
+    0b01100: ('Trigger with ACK', 0, 0),
+    # Reserved
+    # Reserved
+    # Reserved
+    # Reserved
+    # Reserved
+    0b10010: ('Read 4-byte JTAG ID', 0, 0),
+    # Reserved
+    # Reserved
+    # Reserved
+    # Reserved
+    0b10111: ('Stream 32 byte with ACK', 0, 32)
+    # Rest is reserved
+}
+
+
+
+ann_header_tag, ann_header_cmd, ann_header_ch, ann_address, ann_data, \
+    ann_crc, ann_warning = range(7)
+
+class Decoder(srd.Decoder):
+    api_version = 3
+    id = 'sipi'
+    name = 'SIPI (ZipWire)'
+    longname = 'NXP SIPI interface'
+    desc = 'Serial Inter-Processor Interface (SIPI) aka ZipWire, aka HSSL'
+    license = 'gplv2+'
+    inputs = ['lfast']
+    outputs = []
+    tags = ['Embedded/industrial']
+    annotations = (
+        ('header_tag', 'Transaction Tag'),
+        ('header_cmd', 'Command Code'),
+        ('header_ch', 'Channel'),
+        ('address', 'Address'),
+        ('data', 'Data'),
+        ('crc', 'CRC'),
+        ('warning', 'Warning'),
+    )
+    annotation_rows = (
+        ('fields', 'Fields', (ann_header_tag, ann_header_cmd,
+            ann_header_ch, ann_address, ann_data, ann_crc,)),
+        ('warnings', 'Warnings', (ann_warning,)),
+    )
+
+    def __init__(self):
+        self.reset()
+
+    def reset(self):
+        self.byte_len = 0
+        self.frame_len = 0
+
+    def start(self):
+        self.out_ann = self.register(srd.OUTPUT_ANN)
+        self.out_binary = self.register(srd.OUTPUT_BINARY)
+
+    def put_ann(self, ss, es, ann_class, value):
+        self.put(int(ss), int(es), self.out_ann, [ann_class, value])
+
+    def put_header(self, ss_header, es_header, value):
+        ss = ss_header
+        es = ss + 3 * self.bit_len
+        tag = (value & 0xE000) >> 13
+        self.put_ann(ss, es, ann_header_tag, ['{:02X}'.format(tag)])
+
+        ss = es
+        es = ss + 5 * self.bit_len
+        cmd_id = (value & 0x1F00) >> 8
+        cmd_name, self.addr_len, self.data_len = \
+            command_codes.get(cmd_id, ('Reserved ({:02X})'.format(cmd_id), 0, 0))
+        self.frame_len = 2 + 2 + self.addr_len + self.data_len  # +Header +CRC
+        self.put_ann(ss, es, ann_header_cmd, [cmd_name])
+
+        # Bits 4..7 are reserved and should be 0, warn if they're not
+        ss = es
+        es = ss + 4 * self.bit_len
+        reserved_bits = (value & 0x00F0) >> 4
+        if reserved_bits > 0:
+            self.put_ann(ss, es, ann_warning, ['Reserved bits #4..7 should be 0'])
+
+        ss = es
+        es = ss + 3 * self.bit_len
+        ch = (value & 0x000E) >> 1  # See tc27xD_um_v2.2.pdf, Table 20-1
+        self.put_ann(ss, es, ann_header_ch, [str(ch)])
+
+        # Bit 0 is reserved and should be 0, warn if it's not
+        if (value & 0x0001) == 0x0001:
+            ss = es
+            es = ss + self.bit_len
+            self.put_ann(ss, es, ann_warning, ['Reserved bit #0 should be 0'])
+
+    def put_payload(self, data):
+        byte_idx = 0
+        if self.addr_len > 0:
+            for value_tuple in data[:self.addr_len]:
+                ss, es, value = value_tuple
+                self.put_ann(ss, es, ann_address, ['{:02X}'.format(value)])
+            byte_idx = self.addr_len
+
+        if self.data_len > 0:
+            for value_tuple in data[byte_idx:]:
+                ss, es, value = value_tuple
+                self.put_ann(ss, es, ann_data, ['{:02X}'.format(value)])
+
+    def put_crc(self, ss, es, crc_value, crc_payload_data):
+        crc_payload = []
+        for value_tuple in crc_payload_data:
+            crc_payload.append(value_tuple[2])
+
+        calculated_crc = crc_hqx(bytes(crc_payload), 0xFFFF)
+
+        if calculated_crc == crc_value:
+            self.put_ann(ss, es, ann_crc, ['CRC OK'])
+        else:
+            self.put_ann(ss, es, ann_crc, ['Have {:02X} but calculated {:02X}'.format(crc_value, calculated_crc)])
+            self.put_ann(ss, es, ann_warning, ['CRC mismatch'])
+
+    def decode(self, ss, es, data):
+        if len(data) == 1:
+            self.put_ann(ss, es, ann_warning, ['Header too short'])
+            return
+
+        # ss and es are now unused, we use them as local variables instead
+
+        self.bit_len = (data[0][1] - data[0][0]) / 8.0
+
+        byte_idx = 0
+
+        ss = data[byte_idx][0]
+        es = data[byte_idx + 1][1]
+        self.put_header(ss, es, (data[byte_idx][2] << 8) + data[byte_idx + 1][2])
+        byte_idx += 2
+
+        payload_len = self.frame_len - 2 - 2  # -Header -CRC
+        if payload_len > 0:
+            self.put_payload(data[byte_idx:-2])
+            byte_idx += payload_len
+
+        ss = data[byte_idx][0]
+        es = data[byte_idx + 1][1]
+        if byte_idx == len(data) - 2:
+            # CRC is calculated over header + payload bytes
+            self.put_crc(ss, es, (data[byte_idx][2] << 8) + data[byte_idx + 1][2], data[0:-2])
+        else:
+            self.put_ann(ss, es, ann_warning, ['CRC incomplete or missing'])