- 'BIT', <bit>
- 'STUFF BIT', None
- 'EOP', None
+ - 'ERR', None
+ - 'KEEP ALIVE', None
+ - 'RESET', None
<sym>:
- 'J', 'K', 'SE0', or 'SE1'
<bit>:
- - 0 or 1
+ - '0' or '1'
- Note: Symbols like SE0, SE1, and the J that's part of EOP don't yield 'BIT'.
'''
('eop', 'End of packet (EOP)'),
('bit', 'Bit'),
('stuffbit', 'Stuff bit'),
+ ('error', 'Error'),
+ ('keep-alive', 'Low-speed keep-alive'),
+ ('reset', 'Reset'),
)
annotation_rows = (
- ('bits', 'Bits', (4, 5, 6, 7)),
+ ('bits', 'Bits', (4, 5, 6, 7, 8, 9, 10)),
('symbols', 'Symbols', (0, 1, 2, 3)),
)
def __init__(self):
self.samplerate = None
self.oldsym = 'J' # The "idle" state is J.
- self.ss_sop = None
self.ss_block = None
self.samplenum = 0
- self.syms = []
self.bitrate = None
self.bitwidth = None
self.samplepos = None
self.samplenum_target = None
self.samplenum_edge = None
+ self.samplenum_lastedge = 0
self.oldpins = None
self.edgepins = None
self.consecutive_ones = 0
- self.state = 'IDLE'
+ self.state = 'INIT'
def start(self):
self.out_python = self.register(srd.OUTPUT_PYTHON)
self.samplerate = value
self.bitrate = bitrates[self.options['signalling']]
self.bitwidth = float(self.samplerate) / float(self.bitrate)
- self.halfbit = int(self.bitwidth / 2)
def putpx(self, data):
- self.put(self.samplenum, self.samplenum, self.out_python, data)
+ s = self.samplenum_edge
+ self.put(s, s, self.out_python, data)
def putx(self, data):
- self.put(self.samplenum, self.samplenum, self.out_ann, data)
+ s = self.samplenum_edge
+ self.put(s, s, self.out_ann, data)
def putpm(self, data):
- s, h = self.samplenum, self.halfbit
- self.put(self.ss_block - h, s + h, self.out_python, data)
+ e = self.samplenum_edge
+ self.put(self.ss_block, e, self.out_python, data)
def putm(self, data):
- s, h = self.samplenum, self.halfbit
- self.put(self.ss_block - h, s + h, self.out_ann, data)
+ e = self.samplenum_edge
+ self.put(self.ss_block, e, self.out_ann, data)
def putpb(self, data):
- s, h = self.samplenum, self.halfbit
- self.put(self.samplenum_edge, s + h, self.out_python, data)
+ s, e = self.samplenum_lastedge, self.samplenum_edge
+ self.put(s, e, self.out_python, data)
def putb(self, data):
- s, h = self.samplenum, self.halfbit
- self.put(self.samplenum_edge, s + h, self.out_ann, data)
+ s, e = self.samplenum_lastedge, self.samplenum_edge
+ self.put(s, e, self.out_ann, data)
def set_new_target_samplenum(self):
self.samplepos += self.bitwidth;
self.samplenum_target = int(self.samplepos)
+ self.samplenum_lastedge = self.samplenum_edge
self.samplenum_edge = int(self.samplepos - (self.bitwidth / 2))
def wait_for_sop(self, sym):
# Wait for a Start of Packet (SOP), i.e. a J->K symbol change.
- if sym != 'K':
- self.oldsym = sym
+ if sym != 'K' or self.oldsym != 'J':
return
- self.ss_sop = self.samplenum
- self.samplepos = self.ss_sop - (self.bitwidth / 2) + 0.5
+ self.consecutive_ones = 0
+ self.samplepos = self.samplenum - (self.bitwidth / 2) + 0.5
self.set_new_target_samplenum()
self.putpx(['SOP', None])
self.putx([4, ['SOP', 'S']])
self.state = 'GET BIT'
- def handle_bit(self, sym, b):
- if self.consecutive_ones == 6 and b == '0':
- # Stuff bit.
- self.putpb(['STUFF BIT', None])
- self.putb([7, ['Stuff bit: %s' % b, 'SB: %s' % b, '%s' % b]])
- self.consecutive_ones = 0
+ def handle_bit(self, b):
+ if self.consecutive_ones == 6:
+ if b == '0':
+ # Stuff bit.
+ self.putpb(['STUFF BIT', None])
+ self.putb([7, ['Stuff bit: 0', 'SB: 0', '0']])
+ self.consecutive_ones = 0
+ else:
+ self.putpb(['ERR', None])
+ self.putb([8, ['Bit stuff error', 'BS ERR', 'B']])
+ self.state = 'IDLE'
else:
# Normal bit (not a stuff bit).
self.putpb(['BIT', b])
def get_eop(self, sym):
# EOP: SE0 for >= 1 bittime (usually 2 bittimes), then J.
- self.syms.append(sym)
+ self.set_new_target_samplenum()
self.putpb(['SYM', sym])
self.putb(sym_annotation[sym])
- self.set_new_target_samplenum()
self.oldsym = sym
- if self.syms[-2:] == ['SE0', 'J']:
+ if sym == 'SE0':
+ pass
+ elif sym == 'J':
# Got an EOP.
self.putpm(['EOP', None])
self.putm([5, ['EOP', 'E']])
- self.syms, self.state = [], 'IDLE'
- self.consecutive_ones = 0
+ self.state = 'IDLE'
self.bitwidth = float(self.samplerate) / float(self.bitrate)
+ else:
+ self.putpm(['ERR', None])
+ self.putm([8, ['EOP Error', 'EErr', 'E']])
+ self.state = 'IDLE'
def get_bit(self, sym):
+ self.set_new_target_samplenum()
if sym == 'SE0':
- # Start of an EOP. Change state, run get_eop() for this bit.
+ # Start of an EOP. Change state, save edge
self.state = 'GET EOP'
- self.ss_block = self.samplenum
- self.get_eop(sym)
- return
- self.syms.append(sym)
+ self.ss_block = self.samplenum_lastedge
+ else:
+ b = '0' if self.oldsym != sym else '1'
+ self.handle_bit(b)
self.putpb(['SYM', sym])
- b = '0' if self.oldsym != sym else '1'
self.putb(sym_annotation[sym])
if self.oldsym != sym:
edgesym = symbols[self.options['signalling']][tuple(self.edgepins)]
else:
self.bitwidth = self.bitwidth + (0.001 * self.bitwidth)
self.samplepos = self.samplepos + (0.01 * self.bitwidth)
- self.handle_bit(sym, b)
- self.set_new_target_samplenum()
self.oldsym = sym
+ def handle_idle(self, sym):
+ self.samplenum_edge = self.samplenum
+ se0_length = float(self.samplenum - self.samplenum_lastedge) / self.samplerate
+ if se0_length > 2.5e-6: # 2.5us
+ self.putpb(['RESET', None])
+ self.putb([10, ['Reset', 'Res', 'R']])
+ elif se0_length > 1.2e-6 and self.options['signalling'] == 'low-speed':
+ self.putpb(['KEEP ALIVE', None])
+ self.putb([9, ['Keep-alive', 'KA', 'A']])
+ self.state = 'IDLE'
+
def decode(self, ss, es, data):
if not self.samplerate:
raise SamplerateError('Cannot decode without samplerate.')
continue
self.oldpins = pins
sym = symbols[self.options['signalling']][tuple(pins)]
- self.wait_for_sop(sym)
+ if sym == 'SE0':
+ self.samplenum_lastedge = self.samplenum
+ self.state = 'WAIT IDLE'
+ else:
+ self.wait_for_sop(sym)
self.edgepins = pins
elif self.state in ('GET BIT', 'GET EOP'):
# Wait until we're in the middle of the desired bit.
self.get_bit(sym)
elif self.state == 'GET EOP':
self.get_eop(sym)
+ elif self.state == 'WAIT IDLE':
+ if self.oldpins == pins:
+ continue
+ sym = symbols[self.options['signalling']][tuple(pins)]
+ if self.samplenum - self.samplenum_lastedge > 1:
+ self.handle_idle(sym)
+ else:
+ self.wait_for_sop(sym)
+ self.oldpins = pins
+ self.edgepins = pins
+ elif self.state == 'INIT':
+ sym = symbols[self.options['signalling']][tuple(pins)]
+ self.handle_idle(sym)
+ self.oldpins = pins
projects / libsigrokdecode.git / blobdiff