From: Soeren Apel Date: Tue, 28 Jul 2020 10:57:58 +0000 (+0200) Subject: lfast: Enhance LFAST PD X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=4d8b4da74356e2cdd8da75b4ce80c4a17e81b335;p=libsigrokdecode.git lfast: Enhance LFAST PD --- diff --git a/decoders/lfast/__init__.py b/decoders/lfast/__init__.py index 93baae7..a2fd0fe 100644 --- a/decoders/lfast/__init__.py +++ b/decoders/lfast/__init__.py @@ -28,7 +28,8 @@ As with most differential signals, it's sufficient to measure TXP or RXP, no need for a differential probe. The REFCLK used by the hardware isn't needed by this protocol decoder either. -For details see https://www.nxp.com/docs/en/application-note/AN5134.pdf +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/lfast/pd.py b/decoders/lfast/pd.py index cf6c0f2..5cf99b6 100644 --- a/decoders/lfast/pd.py +++ b/decoders/lfast/pd.py @@ -28,8 +28,72 @@ OUTPUT_PYTHON format: 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 @@ -47,14 +111,18 @@ class Decoder(srd.Decoder): 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,)), ) @@ -67,8 +135,10 @@ class Decoder(srd.Decoder): 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): @@ -93,7 +163,7 @@ class Decoder(srd.Decoder): 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 @@ -103,17 +173,32 @@ class Decoder(srd.Decoder): 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: @@ -121,29 +206,49 @@ class Decoder(srd.Decoder): 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: @@ -152,17 +257,21 @@ class Decoder(srd.Decoder): 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: @@ -171,7 +280,12 @@ class Decoder(srd.Decoder): # 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 @@ -189,5 +303,10 @@ class Decoder(srd.Decoder): 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