the LFAST stop bit. It's an array of bytes.
'''
-ann_bit, ann_sync, ann_header, ann_payload, ann_stopbit, ann_warning = range(6)
-state_sync, state_header, state_payload, state_stopbit = range(4)
+# See tc27xD_um_v2.2.pdf, Table 20-10
+payload_sizes = {
+ 0b000: '8 bit',
+ 0b001: '32 bit',
+ 0b010: '64 bit',
+ 0b011: '96 bit',
+ 0b100: '128 bit',
+ 0b101: '256 bit',
+ 0b110: '512 bit',
+ 0b111: '288 bit'
+}
+
+# See tc27xD_um_v2.2.pdf, Table 20-10
+payload_byte_sizes = {
+ 0b000: 1,
+ 0b001: 4,
+ 0b010: 8,
+ 0b011: 12,
+ 0b100: 16,
+ 0b101: 32,
+ 0b110: 64,
+ 0b111: 36
+}
+
+# See tc27xD_um_v2.2.pdf, Table 20-11
+channel_types = {
+ 0b0000: 'Interface Control / PING (32 bit)',
+ 0b0001: 'Unsolicited Status (32 bit)',
+ 0b0010: 'Slave Interface Control / Read',
+ 0b0011: 'CTS Transfer',
+ 0b0100: 'Data Channel A',
+ 0b0101: 'Data Channel B',
+ 0b0110: 'Data Channel C',
+ 0b0111: 'Data Channel D',
+ 0b1000: 'Data Channel E',
+ 0b1001: 'Data Channel F',
+ 0b1010: 'Data Channel G',
+ 0b1011: 'Data Channel H',
+ 0b1100: 'Reserved',
+ 0b1101: 'Reserved',
+ 0b1110: 'Reserved',
+ 0b1111: 'Reserved',
+}
+
+# See tc27xD_um_v2.2.pdf, Table 20-12
+control_payloads = {
+ 0x00: 'PING',
+ 0x01: 'Reserved',
+ 0x02: 'Slave interface clock multiplier start',
+ 0x04: 'Slave interface clock multiplier stop',
+ 0x08: 'Use 5 MBaud for M->S',
+ 0x10: 'Use 320 MBaud for M->S',
+ 0x20: 'Use 5 MBaud for S->M',
+ 0x40: 'Use 20 MBaud for S->M (needs 20 MHz SysClk)',
+ 0x80: 'Use 320 MBaud for S->M',
+ 0x31: 'Enable slave interface transmitter',
+ 0x32: 'Disable slave interface transmitter',
+ 0x34: 'Enable clock test mode',
+ 0x38: 'Disable clock test mode and payload loopback',
+ 0xFF: 'Enable payload loopback',
+}
+
+
+ann_bit, ann_sync, ann_header_pl_size, ann_header_ch_type, ann_header_cts, \
+ ann_payload, ann_control_data, ann_sleepbit, ann_warning = range(9)
+state_sync, state_header, state_payload, state_sleepbit = range(4)
class Decoder(srd.Decoder):
api_version = 3
annotations = (
('bit', 'Bits'),
('sync', 'Sync Pattern'),
- ('header', 'Header'),
+ ('header_pl_size', 'Payload Size'),
+ ('header_ch_type', 'Logical Channel Type'),
+ ('header_cts', 'Clear To Send'),
('payload', 'Payload'),
- ('stop', 'Stop Bit'),
+ ('ctrl_data', 'Control Data'),
+ ('sleep', 'Sleep Bit'),
('warning', 'Warning'),
)
annotation_rows = (
('bits', 'Bits', (ann_bit,)),
- ('fields', 'Fields', (ann_sync, ann_header, ann_payload, ann_stopbit,)),
+ ('fields', 'Fields', (ann_sync, ann_header_pl_size, ann_header_ch_type,
+ ann_header_cts, ann_payload, ann_control_data, ann_sleepbit,)),
('warnings', 'Warnings', (ann_warning,)),
)
self.ss_payload = self.es_payload = 0
self.bits = []
self.payload = []
- self.bit_len = 0
- self.timeout = 0
+ self.payload_size = 0 # Expected number of bytes, as read from header
+ self.bit_len = 0 # Length of one bit time, in samples
+ self.timeout = 0 # desired timeout for next edge, in samples
+ self.ch_type_id = 0 # ID of channel type
self.state = state_sync
def metadata(self, key, value):
if value == 0xA84B:
self.put_ann(self.ss_sync, self.es_bit, ann_sync, ['Sync OK'])
else:
- self.put_ann(self.ss_sync, self.es_bit, ann_warning, ['Wrong Sync Value: {:2X}'.format(value)])
+ self.put_ann(self.ss_sync, self.es_bit, ann_warning, ['Wrong Sync Value: {:02X}'.format(value)])
self.bits = []
self.state = state_header
self.ss_header = self.ss_bit
if len(self.bits) == 8:
+ # See tc27xD_um_v2.2.pdf, Figure 20-47, for the header structure
+ bit_len = (self.es_bit - self.ss_header) / 8
value = bitpack(self.bits)
- self.put_ann(self.ss_header, self.es_bit, ann_header, ['{:2X}'.format(value)])
+
+ ss = self.ss_header
+ es = ss + 3 * bit_len
+ size_id = (value & 0xE0) >> 5
+ size = payload_sizes.get(size_id)
+ self.payload_size = payload_byte_sizes.get(size_id)
+ self.put_ann(int(ss), int(es), ann_header_pl_size, [size])
+
+ ss = es
+ es = ss + 4 * bit_len
+ self.ch_type_id = (value & 0x1E) >> 1
+ ch_type = channel_types.get(self.ch_type_id)
+ self.put_ann(int(ss), int(es), ann_header_ch_type, [ch_type])
+
+ ss = es
+ es = ss + bit_len
+ cts = value & 0x01
+ self.put_ann(int(ss), int(es), ann_header_cts, ['{}'.format(cts)])
+
self.bits = []
self.state = state_payload
def handle_payload(self):
- # 8 bit times without state change are possible (8 low bits) but when
- # there are 9 bit times without state change, we should have seen the
- # stop bit - and only the stop bit
- self.timeout = int(9 * self.bit_len)
-
if len(self.bits) == 1:
self.ss_byte = self.ss_bit
if self.ss_payload == 0:
if len(self.bits) == 8:
value = bitpack(self.bits)
- self.put_ann(self.ss_byte, self.es_bit, ann_payload, ['{:2X}'.format(value)])
+ value_hex = '{:02X}'.format(value)
+
+ # Control transfers have no SIPI payload, show them as control transfers
+ # Check the channel_types list for the meaning of the magic values
+ if (self.ch_type_id >= 0b0100) and (self.ch_type_id <= 0b1011):
+ self.put_ann(self.ss_byte, self.es_bit, ann_payload, [value_hex])
+ else:
+ # Control transfers are 8-bit transfers, so only evaluate the first byte
+ if len(self.payload) == 0:
+ ctrl_data = control_payloads.get(value, value_hex)
+ self.put_ann(self.ss_byte, self.es_bit, ann_control_data, [ctrl_data])
+ else:
+ self.put_ann(self.ss_byte, self.es_bit, ann_control_data, [value_hex])
+
self.bits = []
self.payload.append(value)
self.es_payload = self.es_bit
+
+ self.timeout = int((self.payload_size - len(self.payload)) * 8 * self.bit_len)
+
+ if (len(self.payload) == self.payload_size):
+ self.timeout = int(1.4 * self.bit_len)
+ self.bits = []
+ self.state = state_sleepbit
- def handle_stopbit(self):
- if len(self.bits) > 1:
- self.put_ann(self.ss_bit, self.es_bit, ann_warning, ['Expected only the stop bit, got {} bits'.format(len(self.bits))])
+ def handle_sleepbit(self):
+ if len(self.bits) == 0:
+ self.put_ann(self.ss_bit, self.es_bit, ann_sleepbit, ['No LVDS sleep mode request', 'No sleep', 'N'])
+ elif len(self.bits) > 1:
+ self.put_ann(self.ss_bit, self.es_bit, ann_warning, ['Expected only the sleep bit, got {} bits instead'.format(len(self.bits))])
else:
- if self.bits[0] == 1:
- self.put_ann(self.ss_bit, self.es_bit, ann_stopbit, ['Stop Bit', 'Stop', 'S'])
+ if self.bits[0] == 1:
+ self.put_ann(self.ss_bit, self.es_bit, ann_sleepbit, ['LVDS sleep mode request', 'Sleep', 'Y'])
else:
- self.put_ann(self.ss_bit, self.es_bit, ann_warning, ['Stop Bit must be 1', 'Stop not 1', 'S'])
+ self.put_ann(self.ss_bit, self.es_bit, ann_sleepbit, ['No LVDS sleep mode request', 'No sleep', 'N'])
- # We send the payload out regardless of the stop bit's status so that
- # any intermediate results can be decoded by a stacked decoder
- self.put_payload()
- self.payload = []
- self.ss_payload = 0
-
- self.timeout = 0
- self.bits = []
- self.state = state_sync
+ # We only send the payload out if this is an actual data transfer;
+ # check the channel_types list for the meaning of the magic values
+ if (self.ch_type_id >= 0b0100) and (self.ch_type_id <= 0b1011):
+ if len(self.payload) > 0:
+ self.put_payload()
+
+ self.reset()
def decode(self):
while True:
else:
rising_edge, = self.wait([{0: 'e'}, {'skip': self.timeout}])
- # If this is the first bit, we only update ss
+ # If this is the first edge, we only update ss
if self.ss == 0:
self.ss = self.samplenum
continue
-
+
self.es = self.samplenum
- # Check for the stop bit if this is a timeout condition
- if (self.timeout > 0) and (self.es - self.ss >= self.timeout):
- self.handle_stopbit()
- continue
+ if int(self.es - self.ss) == 0:
+ continue
+
+ # Check for the sleep bit if this is a timeout condition
+ if (self.timeout > 0) and (self.es - self.ss == self.timeout):
+ rising_edge = ~rising_edge
+ if self.state == state_sleepbit:
+ self.handle_sleepbit()
# We use the first bit to deduce the bit length
if self.bit_len == 0:
# Determine number of bits covered by this edge
bit_count = (self.es - self.ss) / self.bit_len
bit_count = int(decimal.Decimal(bit_count).to_integral_value())
-
+
+ if bit_count == 0:
+ self.put_ann(self.ss, self.es, ann_warning, ['Bit time too short'])
+ self.reset()
+ continue
+
bit_value = '0' if rising_edge else '1'
divided_len = (self.es - self.ss) / bit_count
self.handle_header()
elif self.state == state_payload:
self.handle_payload()
+ elif self.state == state_sleepbit:
+ self.handle_sleepbit()
+ break
- self.ss = self.samplenum
+ # Only update ss if we didn't just perform a reset
+ if self.ss > 0:
+ self.ss = self.samplenum
projects / libsigrokdecode.git / commitdiff