##
## This file is part of the libsigrokdecode project.
##
-## Copyright (C) 2011-2013 Uwe Hermann <uwe@hermann-uwe.de>
+## Copyright (C) 2011-2014 Uwe Hermann <uwe@hermann-uwe.de>
##
## 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
## 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, write to the Free Software
-## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
##
-# UART protocol decoder
-
import sigrokdecode as srd
+from common.srdhelper import bitpack
+from math import floor, ceil
'''
-Protocol output format:
+OUTPUT_PYTHON format:
-UART packet:
-[<packet-type>, <rxtx>, <packet-data>]
+Packet:
+[<ptype>, <rxtx>, <pdata>]
-This is the list of <packet-type>s and their respective <packet-data>:
+This is the list of <ptype>s and their respective <pdata> values:
- 'STARTBIT': The data is the (integer) value of the start bit (0/1).
- - 'DATA': The data is the (integer) value of the UART data. Valid values
- range from 0 to 512 (as the data can be up to 9 bits in size).
+ - 'DATA': This is always a tuple containing two items:
+ - 1st item: the (integer) value of the UART data. Valid values
+ range from 0 to 511 (as the data can be up to 9 bits in size).
+ - 2nd item: the list of individual data bits and their ss/es numbers.
- 'PARITYBIT': The data is the (integer) value of the parity bit (0/1).
- 'STOPBIT': The data is the (integer) value of the stop bit (0 or 1).
- 'INVALID STARTBIT': The data is the (integer) value of the start bit (0/1).
- 'INVALID STOPBIT': The data is the (integer) value of the stop bit (0/1).
- 'PARITY ERROR': The data is a tuple with two entries. The first one is
the expected parity value, the second is the actual parity value.
- - TODO: Frame error?
+ - 'BREAK': The data is always 0.
+ - 'FRAME': The data is always a tuple containing two items: The (integer)
+ value of the UART data, and a boolean which reflects the validity of the
+ UART frame.
The <rxtx> field is 0 for RX packets, 1 for TX packets.
'''
return (ones % 2) == 1
elif parity_type == 'even':
return (ones % 2) == 0
- else:
- raise Exception('Invalid parity type: %d' % parity_type)
+
+class SamplerateError(Exception):
+ pass
+
+class ChannelError(Exception):
+ pass
class Decoder(srd.Decoder):
- api_version = 1
+ api_version = 3
id = 'uart'
name = 'UART'
longname = 'Universal Asynchronous Receiver/Transmitter'
license = 'gplv2+'
inputs = ['logic']
outputs = ['uart']
- probes = [
+ tags = ['Embedded/industrial']
+ optional_channels = (
# Allow specifying only one of the signals, e.g. if only one data
# direction exists (or is relevant).
{'id': 'rx', 'name': 'RX', 'desc': 'UART receive line'},
{'id': 'tx', 'name': 'TX', 'desc': 'UART transmit line'},
- ]
- optional_probes = []
- options = {
- 'baudrate': ['Baud rate', 115200],
- 'num_data_bits': ['Data bits', 8], # Valid: 5-9.
- 'parity_type': ['Parity type', 'none'],
- 'parity_check': ['Check parity?', 'yes'], # TODO: Bool supported?
- 'num_stop_bits': ['Stop bit(s)', '1'], # String! 0, 0.5, 1, 1.5.
- 'bit_order': ['Bit order', 'lsb-first'],
- 'format': ['Data format', 'ascii'], # ascii/dec/hex/oct/bin
- # TODO: Options to invert the signal(s).
- }
- annotations = [
- ['Data', 'UART data'],
- ['Start bits', 'UART start bits'],
- ['Parity bits', 'UART parity bits'],
- ['Stop bits', 'UART stop bits'],
- ['Warnings', 'Warnings'],
- ]
+ )
+ options = (
+ {'id': 'baudrate', 'desc': 'Baud rate', 'default': 115200},
+ {'id': 'num_data_bits', 'desc': 'Data bits', 'default': 8,
+ 'values': (5, 6, 7, 8, 9)},
+ {'id': 'parity_type', 'desc': 'Parity type', 'default': 'none',
+ 'values': ('none', 'odd', 'even', 'zero', 'one')},
+ {'id': 'parity_check', 'desc': 'Check parity?', 'default': 'yes',
+ 'values': ('yes', 'no')},
+ {'id': 'num_stop_bits', 'desc': 'Stop bits', 'default': 1.0,
+ 'values': (0.0, 0.5, 1.0, 1.5)},
+ {'id': 'bit_order', 'desc': 'Bit order', 'default': 'lsb-first',
+ 'values': ('lsb-first', 'msb-first')},
+ {'id': 'format', 'desc': 'Data format', 'default': 'hex',
+ 'values': ('ascii', 'dec', 'hex', 'oct', 'bin')},
+ {'id': 'invert_rx', 'desc': 'Invert RX?', 'default': 'no',
+ 'values': ('yes', 'no')},
+ {'id': 'invert_tx', 'desc': 'Invert TX?', 'default': 'no',
+ 'values': ('yes', 'no')},
+ {'id': 'rx_packet_delimiter', 'desc': 'RX packet delimiter (decimal)',
+ 'default': -1},
+ {'id': 'tx_packet_delimiter', 'desc': 'TX packet delimiter (decimal)',
+ 'default': -1},
+ {'id': 'rx_packet_len', 'desc': 'RX packet length', 'default': -1},
+ {'id': 'tx_packet_len', 'desc': 'TX packet length', 'default': -1},
+ )
+ annotations = (
+ ('rx-data', 'RX data'),
+ ('tx-data', 'TX data'),
+ ('rx-start', 'RX start bits'),
+ ('tx-start', 'TX start bits'),
+ ('rx-parity-ok', 'RX parity OK bits'),
+ ('tx-parity-ok', 'TX parity OK bits'),
+ ('rx-parity-err', 'RX parity error bits'),
+ ('tx-parity-err', 'TX parity error bits'),
+ ('rx-stop', 'RX stop bits'),
+ ('tx-stop', 'TX stop bits'),
+ ('rx-warnings', 'RX warnings'),
+ ('tx-warnings', 'TX warnings'),
+ ('rx-data-bits', 'RX data bits'),
+ ('tx-data-bits', 'TX data bits'),
+ ('rx-break', 'RX break'),
+ ('tx-break', 'TX break'),
+ ('rx-packet', 'RX packet'),
+ ('tx-packet', 'TX packet'),
+ )
+ annotation_rows = (
+ ('rx-data', 'RX', (0, 2, 4, 6, 8)),
+ ('rx-data-bits', 'RX bits', (12,)),
+ ('rx-warnings', 'RX warnings', (10,)),
+ ('rx-break', 'RX break', (14,)),
+ ('rx-packets', 'RX packets', (16,)),
+ ('tx-data', 'TX', (1, 3, 5, 7, 9)),
+ ('tx-data-bits', 'TX bits', (13,)),
+ ('tx-warnings', 'TX warnings', (11,)),
+ ('tx-break', 'TX break', (15,)),
+ ('tx-packets', 'TX packets', (17,)),
+ )
+ binary = (
+ ('rx', 'RX dump'),
+ ('tx', 'TX dump'),
+ ('rxtx', 'RX/TX dump'),
+ )
+ idle_state = ['WAIT FOR START BIT', 'WAIT FOR START BIT']
def putx(self, rxtx, data):
- s, halfbit = self.startsample[rxtx], int(self.bit_width / 2)
- self.put(s - halfbit, self.samplenum + halfbit, self.out_ann, data)
+ s, halfbit = self.startsample[rxtx], self.bit_width / 2.0
+ self.put(s - floor(halfbit), self.samplenum + ceil(halfbit), self.out_ann, data)
+
+ def putx_packet(self, rxtx, data):
+ s, halfbit = self.ss_packet[rxtx], self.bit_width / 2.0
+ self.put(s - floor(halfbit), self.samplenum + ceil(halfbit), self.out_ann, data)
+
+ def putpx(self, rxtx, data):
+ s, halfbit = self.startsample[rxtx], self.bit_width / 2.0
+ self.put(s - floor(halfbit), self.samplenum + ceil(halfbit), self.out_python, data)
def putg(self, data):
- s, halfbit = self.samplenum, int(self.bit_width / 2)
- self.put(s - halfbit, s + halfbit, self.out_ann, data)
+ s, halfbit = self.samplenum, self.bit_width / 2.0
+ self.put(s - floor(halfbit), s + ceil(halfbit), self.out_ann, data)
def putp(self, data):
- s, halfbit = self.samplenum, int(self.bit_width / 2)
- self.put(s - halfbit, s + halfbit, self.out_proto, data)
+ s, halfbit = self.samplenum, self.bit_width / 2.0
+ self.put(s - floor(halfbit), s + ceil(halfbit), self.out_python, data)
- def __init__(self, **kwargs):
+ def putgse(self, ss, es, data):
+ self.put(ss, es, self.out_ann, data)
+
+ def putpse(self, ss, es, data):
+ self.put(ss, es, self.out_python, data)
+
+ def putbin(self, rxtx, data):
+ s, halfbit = self.startsample[rxtx], self.bit_width / 2.0
+ self.put(s - floor(halfbit), self.samplenum + ceil(halfbit), self.out_binary, data)
+
+ def __init__(self):
+ self.reset()
+
+ def reset(self):
+ self.samplerate = None
self.samplenum = 0
self.frame_start = [-1, -1]
+ self.frame_valid = [None, None]
self.startbit = [-1, -1]
self.cur_data_bit = [0, 0]
- self.databyte = [0, 0]
+ self.datavalue = [0, 0]
self.paritybit = [-1, -1]
self.stopbit1 = [-1, -1]
self.startsample = [-1, -1]
self.state = ['WAIT FOR START BIT', 'WAIT FOR START BIT']
- self.oldbit = [1, 1]
- self.oldpins = [1, 1]
-
- def start(self, metadata):
- self.samplerate = metadata['samplerate']
- self.out_proto = self.add(srd.OUTPUT_PROTO, 'uart')
- self.out_ann = self.add(srd.OUTPUT_ANN, 'uart')
-
- # The width of one UART bit in number of samples.
- self.bit_width = \
- float(self.samplerate) / float(self.options['baudrate'])
-
- def report(self):
- pass
-
- # Return true if we reached the middle of the desired bit, false otherwise.
- def reached_bit(self, rxtx, bitnum):
+ self.databits = [[], []]
+ self.break_start = [None, None]
+ self.packet_cache = [[], []]
+ self.ss_packet, self.es_packet = [None, None], [None, None]
+ self.idle_start = [None, None]
+
+ def start(self):
+ self.out_python = self.register(srd.OUTPUT_PYTHON)
+ self.out_binary = self.register(srd.OUTPUT_BINARY)
+ self.out_ann = self.register(srd.OUTPUT_ANN)
+ self.bw = (self.options['num_data_bits'] + 7) // 8
+
+ def metadata(self, key, value):
+ if key == srd.SRD_CONF_SAMPLERATE:
+ self.samplerate = value
+ # The width of one UART bit in number of samples.
+ self.bit_width = float(self.samplerate) / float(self.options['baudrate'])
+
+ def get_sample_point(self, rxtx, bitnum):
+ # Determine absolute sample number of a bit slot's sample point.
# bitpos is the samplenumber which is in the middle of the
# specified UART bit (0 = start bit, 1..x = data, x+1 = parity bit
# (if used) or the first stop bit, and so on).
- bitpos = self.frame_start[rxtx] + (self.bit_width / 2.0)
+ # The samples within bit are 0, 1, ..., (bit_width - 1), therefore
+ # index of the middle sample within bit window is (bit_width - 1) / 2.
+ bitpos = self.frame_start[rxtx] + (self.bit_width - 1) / 2.0
bitpos += bitnum * self.bit_width
- if self.samplenum >= bitpos:
- return True
- return False
-
- def reached_bit_last(self, rxtx, bitnum):
- bitpos = self.frame_start[rxtx] + ((bitnum + 1) * self.bit_width)
- if self.samplenum >= bitpos:
- return True
- return False
-
- def wait_for_start_bit(self, rxtx, old_signal, signal):
- # The start bit is always 0 (low). As the idle UART (and the stop bit)
- # level is 1 (high), the beginning of a start bit is a falling edge.
- if not (old_signal == 1 and signal == 0):
- return
+ return bitpos
+ def wait_for_start_bit(self, rxtx, signal):
# Save the sample number where the start bit begins.
self.frame_start[rxtx] = self.samplenum
+ self.frame_valid[rxtx] = True
self.state[rxtx] = 'GET START BIT'
def get_start_bit(self, rxtx, signal):
- # Skip samples until we're in the middle of the start bit.
- if not self.reached_bit(rxtx, 0):
- return
-
self.startbit[rxtx] = signal
- # The startbit must be 0. If not, we report an error.
+ # The startbit must be 0. If not, we report an error and wait
+ # for the next start bit (assuming this one was spurious).
if self.startbit[rxtx] != 0:
self.putp(['INVALID STARTBIT', rxtx, self.startbit[rxtx]])
- # TODO: Abort? Ignore rest of the frame?
+ self.putg([rxtx + 10, ['Frame error', 'Frame err', 'FE']])
+ self.frame_valid[rxtx] = False
+ es = self.samplenum + ceil(self.bit_width / 2.0)
+ self.putpse(self.frame_start[rxtx], es, ['FRAME', rxtx,
+ (self.datavalue[rxtx], self.frame_valid[rxtx])])
+ self.state[rxtx] = 'WAIT FOR START BIT'
+ return
self.cur_data_bit[rxtx] = 0
- self.databyte[rxtx] = 0
+ self.datavalue[rxtx] = 0
self.startsample[rxtx] = -1
- self.state[rxtx] = 'GET DATA BITS'
-
self.putp(['STARTBIT', rxtx, self.startbit[rxtx]])
- self.putg([1, ['Start bit', 'Start', 'S']])
+ self.putg([rxtx + 2, ['Start bit', 'Start', 'S']])
- def get_data_bits(self, rxtx, signal):
- # Skip samples until we're in the middle of the desired data bit.
- if not self.reached_bit(rxtx, self.cur_data_bit[rxtx] + 1):
+ self.state[rxtx] = 'GET DATA BITS'
+
+ def handle_packet(self, rxtx):
+ d = 'rx' if (rxtx == RX) else 'tx'
+ delim = self.options[d + '_packet_delimiter']
+ plen = self.options[d + '_packet_len']
+ if delim == -1 and plen == -1:
return
+ # Cache data values until we see the delimiter and/or the specified
+ # packet length has been reached (whichever happens first).
+ if len(self.packet_cache[rxtx]) == 0:
+ self.ss_packet[rxtx] = self.startsample[rxtx]
+ self.packet_cache[rxtx].append(self.datavalue[rxtx])
+ if self.datavalue[rxtx] == delim or len(self.packet_cache[rxtx]) == plen:
+ self.es_packet[rxtx] = self.samplenum
+ s = ''
+ for b in self.packet_cache[rxtx]:
+ s += self.format_value(b)
+ if self.options['format'] != 'ascii':
+ s += ' '
+ if self.options['format'] != 'ascii' and s[-1] == ' ':
+ s = s[:-1] # Drop trailing space.
+ self.putx_packet(rxtx, [16 + rxtx, [s]])
+ self.packet_cache[rxtx] = []
+
+ def get_data_bits(self, rxtx, signal):
# Save the sample number of the middle of the first data bit.
if self.startsample[rxtx] == -1:
self.startsample[rxtx] = self.samplenum
- # Get the next data bit in LSB-first or MSB-first fashion.
- if self.options['bit_order'] == 'lsb-first':
- self.databyte[rxtx] >>= 1
- self.databyte[rxtx] |= \
- (signal << (self.options['num_data_bits'] - 1))
- elif self.options['bit_order'] == 'msb-first':
- self.databyte[rxtx] <<= 1
- self.databyte[rxtx] |= (signal << 0)
- else:
- raise Exception('Invalid bit order value: %s',
- self.options['bit_order'])
+ self.putg([rxtx + 12, ['%d' % signal]])
+
+ # Store individual data bits and their start/end samplenumbers.
+ s, halfbit = self.samplenum, int(self.bit_width / 2)
+ self.databits[rxtx].append([signal, s - halfbit, s + halfbit])
# Return here, unless we already received all data bits.
- if self.cur_data_bit[rxtx] < self.options['num_data_bits'] - 1:
- self.cur_data_bit[rxtx] += 1
+ self.cur_data_bit[rxtx] += 1
+ if self.cur_data_bit[rxtx] < self.options['num_data_bits']:
return
- self.state[rxtx] = 'GET PARITY BIT'
+ # Convert accumulated data bits to a data value.
+ bits = [b[0] for b in self.databits[rxtx]]
+ if self.options['bit_order'] == 'msb-first':
+ bits.reverse()
+ self.datavalue[rxtx] = bitpack(bits)
+ self.putpx(rxtx, ['DATA', rxtx,
+ (self.datavalue[rxtx], self.databits[rxtx])])
- self.putp(['DATA', rxtx, self.databyte[rxtx]])
-
- s = 'RX: ' if (rxtx == RX) else 'TX: '
- b, f = self.databyte[rxtx], self.options['format']
- if f == 'ascii':
- self.putx(rxtx, [0, [s + chr(b)]])
- elif f == 'dec':
- self.putx(rxtx, [0, [s + str(b)]])
- elif f == 'hex':
- self.putx(rxtx, [0, [s + hex(b)[2:].zfill(2).upper()]])
- elif f == 'oct':
- self.putx(rxtx, [0, [s + oct(b)[2:].zfill(3)]])
- elif f == 'bin':
- self.putx(rxtx, [0, [s + bin(b)[2:].zfill(8)]])
- else:
- raise Exception('Invalid data format option: %s' % f)
+ b = self.datavalue[rxtx]
+ formatted = self.format_value(b)
+ if formatted is not None:
+ self.putx(rxtx, [rxtx, [formatted]])
- def get_parity_bit(self, rxtx, signal):
- # If no parity is used/configured, skip to the next state immediately.
+ bdata = b.to_bytes(self.bw, byteorder='big')
+ self.putbin(rxtx, [rxtx, bdata])
+ self.putbin(rxtx, [2, bdata])
+
+ self.handle_packet(rxtx)
+
+ self.databits[rxtx] = []
+
+ # Advance to either reception of the parity bit, or reception of
+ # the STOP bits if parity is not applicable.
+ self.state[rxtx] = 'GET PARITY BIT'
if self.options['parity_type'] == 'none':
self.state[rxtx] = 'GET STOP BITS'
- return
- # Skip samples until we're in the middle of the parity bit.
- if not self.reached_bit(rxtx, self.options['num_data_bits'] + 1):
- return
+ def format_value(self, v):
+ # Format value 'v' according to configured options.
+ # Reflects the user selected kind of representation, as well as
+ # the number of data bits in the UART frames.
+
+ fmt, bits = self.options['format'], self.options['num_data_bits']
+
+ # Assume "is printable" for values from 32 to including 126,
+ # below 32 is "control" and thus not printable, above 127 is
+ # "not ASCII" in its strict sense, 127 (DEL) is not printable,
+ # fall back to hex representation for non-printables.
+ if fmt == 'ascii':
+ if v in range(32, 126 + 1):
+ return chr(v)
+ hexfmt = "[{:02X}]" if bits <= 8 else "[{:03X}]"
+ return hexfmt.format(v)
+
+ # Mere number to text conversion without prefix and padding
+ # for the "decimal" output format.
+ if fmt == 'dec':
+ return "{:d}".format(v)
+
+ # Padding with leading zeroes for hex/oct/bin formats, but
+ # without a prefix for density -- since the format is user
+ # specified, there is no ambiguity.
+ if fmt == 'hex':
+ digits = (bits + 4 - 1) // 4
+ fmtchar = "X"
+ elif fmt == 'oct':
+ digits = (bits + 3 - 1) // 3
+ fmtchar = "o"
+ elif fmt == 'bin':
+ digits = bits
+ fmtchar = "b"
+ else:
+ fmtchar = None
+ if fmtchar is not None:
+ fmt = "{{:0{:d}{:s}}}".format(digits, fmtchar)
+ return fmt.format(v)
- self.paritybit[rxtx] = signal
+ return None
- self.state[rxtx] = 'GET STOP BITS'
+ def get_parity_bit(self, rxtx, signal):
+ self.paritybit[rxtx] = signal
if parity_ok(self.options['parity_type'], self.paritybit[rxtx],
- self.databyte[rxtx], self.options['num_data_bits']):
+ self.datavalue[rxtx], self.options['num_data_bits']):
self.putp(['PARITYBIT', rxtx, self.paritybit[rxtx]])
- self.putg([2, ['Parity bit', 'Parity', 'P']])
+ self.putg([rxtx + 4, ['Parity bit', 'Parity', 'P']])
else:
# TODO: Return expected/actual parity values.
self.putp(['PARITY ERROR', rxtx, (0, 1)]) # FIXME: Dummy tuple...
- self.putg([4, ['Parity error', 'Parity err', 'PE']])
+ self.putg([rxtx + 6, ['Parity error', 'Parity err', 'PE']])
+ self.frame_valid[rxtx] = False
+
+ self.state[rxtx] = 'GET STOP BITS'
# TODO: Currently only supports 1 stop bit.
def get_stop_bits(self, rxtx, signal):
- # Skip samples until we're in the middle of the stop bit(s).
- skip_parity = 0 if self.options['parity_type'] == 'none' else 1
- b = self.options['num_data_bits'] + 1 + skip_parity
- if not self.reached_bit(rxtx, b):
- return
-
self.stopbit1[rxtx] = signal
# Stop bits must be 1. If not, we report an error.
if self.stopbit1[rxtx] != 1:
self.putp(['INVALID STOPBIT', rxtx, self.stopbit1[rxtx]])
- self.putg([4, ['Frame error', 'Frame err', 'FE']])
- # TODO: Abort? Ignore the frame? Other?
+ self.putg([rxtx + 10, ['Frame error', 'Frame err', 'FE']])
+ self.frame_valid[rxtx] = False
+
+ self.putp(['STOPBIT', rxtx, self.stopbit1[rxtx]])
+ self.putg([rxtx + 4, ['Stop bit', 'Stop', 'T']])
+
+ # Pass the complete UART frame to upper layers.
+ es = self.samplenum + ceil(self.bit_width / 2.0)
+ self.putpse(self.frame_start[rxtx], es, ['FRAME', rxtx,
+ (self.datavalue[rxtx], self.frame_valid[rxtx])])
self.state[rxtx] = 'WAIT FOR START BIT'
+ self.idle_start[rxtx] = self.frame_start[rxtx] + self.frame_len_sample_count
- self.putp(['STOPBIT', rxtx, self.stopbit1[rxtx]])
- self.putg([3, ['Stop bit', 'Stop', 'T']])
-
- def decode(self, ss, es, data):
- # TODO: Either RX or TX could be omitted (optional probe).
- for (self.samplenum, pins) in data:
-
- # Note: Ignoring identical samples here for performance reasons
- # is not possible for this PD, at least not in the current state.
- # if self.oldpins == pins:
- # continue
- self.oldpins, (rx, tx) = pins, pins
-
- # State machine.
- for rxtx in (RX, TX):
- signal = rx if (rxtx == RX) else tx
-
- if self.state[rxtx] == 'WAIT FOR START BIT':
- self.wait_for_start_bit(rxtx, self.oldbit[rxtx], signal)
- elif self.state[rxtx] == 'GET START BIT':
- self.get_start_bit(rxtx, signal)
- elif self.state[rxtx] == 'GET DATA BITS':
- self.get_data_bits(rxtx, signal)
- elif self.state[rxtx] == 'GET PARITY BIT':
- self.get_parity_bit(rxtx, signal)
- elif self.state[rxtx] == 'GET STOP BITS':
- self.get_stop_bits(rxtx, signal)
- else:
- raise Exception('Invalid state: %s' % self.state[rxtx])
-
- # Save current RX/TX values for the next round.
- self.oldbit[rxtx] = signal
+ def handle_break(self, rxtx):
+ self.putpse(self.frame_start[rxtx], self.samplenum,
+ ['BREAK', rxtx, 0])
+ self.putgse(self.frame_start[rxtx], self.samplenum,
+ [rxtx + 14, ['Break condition', 'Break', 'Brk', 'B']])
+ self.state[rxtx] = 'WAIT FOR START BIT'
+ def get_wait_cond(self, rxtx, inv):
+ # Return condititions that are suitable for Decoder.wait(). Those
+ # conditions either match the falling edge of the START bit, or
+ # the sample point of the next bit time.
+ state = self.state[rxtx]
+ if state == 'WAIT FOR START BIT':
+ return {rxtx: 'r' if inv else 'f'}
+ if state == 'GET START BIT':
+ bitnum = 0
+ elif state == 'GET DATA BITS':
+ bitnum = 1 + self.cur_data_bit[rxtx]
+ elif state == 'GET PARITY BIT':
+ bitnum = 1 + self.options['num_data_bits']
+ elif state == 'GET STOP BITS':
+ bitnum = 1 + self.options['num_data_bits']
+ bitnum += 0 if self.options['parity_type'] == 'none' else 1
+ want_num = ceil(self.get_sample_point(rxtx, bitnum))
+ return {'skip': want_num - self.samplenum}
+
+ def get_idle_cond(self, rxtx, inv):
+ # Return a condition that corresponds to the (expected) end of
+ # the next frame, assuming that it will be an "idle frame"
+ # (constant high input level for the frame's length).
+ if self.idle_start[rxtx] is None:
+ return None
+ end_of_frame = self.idle_start[rxtx] + self.frame_len_sample_count
+ if end_of_frame < self.samplenum:
+ return None
+ return {'skip': end_of_frame - self.samplenum}
+
+ def inspect_sample(self, rxtx, signal, inv):
+ # Inspect a sample returned by .wait() for the specified UART line.
+ if inv:
+ signal = not signal
+
+ state = self.state[rxtx]
+ if state == 'WAIT FOR START BIT':
+ self.wait_for_start_bit(rxtx, signal)
+ elif state == 'GET START BIT':
+ self.get_start_bit(rxtx, signal)
+ elif state == 'GET DATA BITS':
+ self.get_data_bits(rxtx, signal)
+ elif state == 'GET PARITY BIT':
+ self.get_parity_bit(rxtx, signal)
+ elif state == 'GET STOP BITS':
+ self.get_stop_bits(rxtx, signal)
+
+ def inspect_edge(self, rxtx, signal, inv):
+ # Inspect edges, independently from traffic, to detect break conditions.
+ if inv:
+ signal = not signal
+ if not signal:
+ # Signal went low. Start another interval.
+ self.break_start[rxtx] = self.samplenum
+ return
+ # Signal went high. Was there an extended period with low signal?
+ if self.break_start[rxtx] is None:
+ return
+ diff = self.samplenum - self.break_start[rxtx]
+ if diff >= self.break_min_sample_count:
+ self.handle_break(rxtx)
+ self.break_start[rxtx] = None
+
+ def inspect_idle(self, rxtx, signal, inv):
+ # Check each edge and each period of stable input (either level).
+ # Can derive the "idle frame period has passed" condition.
+ if inv:
+ signal = not signal
+ if not signal:
+ # Low input, cease inspection.
+ self.idle_start[rxtx] = None
+ return
+ # High input, either just reached, or still stable.
+ if self.idle_start[rxtx] is None:
+ self.idle_start[rxtx] = self.samplenum
+ diff = self.samplenum - self.idle_start[rxtx]
+ if diff < self.frame_len_sample_count:
+ return
+ ss, es = self.idle_start[rxtx], self.samplenum
+ self.putpse(ss, es, ['IDLE', rxtx, 0])
+ self.idle_start[rxtx] = self.samplenum
+
+ def decode(self):
+ if not self.samplerate:
+ raise SamplerateError('Cannot decode without samplerate.')
+
+ has_pin = [self.has_channel(ch) for ch in (RX, TX)]
+ if has_pin == [False, False]:
+ raise ChannelError('Either TX or RX (or both) pins required.')
+
+ opt = self.options
+ inv = [opt['invert_rx'] == 'yes', opt['invert_tx'] == 'yes']
+ cond_data_idx = [None] * len(has_pin)
+
+ # Determine the number of samples for a complete frame's time span.
+ # A period of low signal (at least) that long is a break condition.
+ frame_samples = 1 # START
+ frame_samples += self.options['num_data_bits']
+ frame_samples += 0 if self.options['parity_type'] == 'none' else 1
+ frame_samples += self.options['num_stop_bits']
+ frame_samples *= self.bit_width
+ self.frame_len_sample_count = ceil(frame_samples)
+ self.break_min_sample_count = self.frame_len_sample_count
+ cond_edge_idx = [None] * len(has_pin)
+ cond_idle_idx = [None] * len(has_pin)
+
+ while True:
+ conds = []
+ if has_pin[RX]:
+ cond_data_idx[RX] = len(conds)
+ conds.append(self.get_wait_cond(RX, inv[RX]))
+ cond_edge_idx[RX] = len(conds)
+ conds.append({RX: 'e'})
+ cond_idle_idx[RX] = None
+ idle_cond = self.get_idle_cond(RX, inv[RX])
+ if idle_cond:
+ cond_idle_idx[RX] = len(conds)
+ conds.append(idle_cond)
+ if has_pin[TX]:
+ cond_data_idx[TX] = len(conds)
+ conds.append(self.get_wait_cond(TX, inv[TX]))
+ cond_edge_idx[TX] = len(conds)
+ conds.append({TX: 'e'})
+ cond_idle_idx[TX] = None
+ idle_cond = self.get_idle_cond(TX, inv[TX])
+ if idle_cond:
+ cond_idle_idx[TX] = len(conds)
+ conds.append(idle_cond)
+ (rx, tx) = self.wait(conds)
+ if cond_data_idx[RX] is not None and self.matched[cond_data_idx[RX]]:
+ self.inspect_sample(RX, rx, inv[RX])
+ if cond_edge_idx[RX] is not None and self.matched[cond_edge_idx[RX]]:
+ self.inspect_edge(RX, rx, inv[RX])
+ self.inspect_idle(RX, rx, inv[RX])
+ if cond_idle_idx[RX] is not None and self.matched[cond_idle_idx[RX]]:
+ self.inspect_idle(RX, rx, inv[RX])
+ if cond_data_idx[TX] is not None and self.matched[cond_data_idx[TX]]:
+ self.inspect_sample(TX, tx, inv[TX])
+ if cond_edge_idx[TX] is not None and self.matched[cond_edge_idx[TX]]:
+ self.inspect_edge(TX, tx, inv[TX])
+ self.inspect_idle(TX, tx, inv[TX])
+ if cond_idle_idx[TX] is not None and self.matched[cond_idle_idx[TX]]:
+ self.inspect_idle(TX, tx, inv[TX])
projects / libsigrokdecode.git / blobdiff