X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=blobdiff_plain;f=decoders%2Fi2c.py;h=15ef9c617dfb1526f6baf17914d71f2eca578cd5;hp=1c4903b0dfe24c33b6d3d8d83b2cb272aeed1c1b;hb=bf1c3f4db0ffbc05f29f81541c551c691ccd2ba7;hpb=bc5f5a434e148db1843be7b02b95a35d21237702 diff --git a/decoders/i2c.py b/decoders/i2c.py index 1c4903b..15ef9c6 100644 --- a/decoders/i2c.py +++ b/decoders/i2c.py @@ -65,87 +65,59 @@ # TODO: Implement support for 7bit and 10bit slave addresses. # TODO: Implement support for inverting SDA/SCL levels (0->1 and 1->0). # TODO: Implement support for detecting various bus errors. - -# -# I2C output format: -# -# The output consists of a (Python) list of I2C "packets", each of which -# has an (implicit) index number (its index in the list). -# Each packet consists of a Python dict with certain key/value pairs. -# -# TODO: Make this a list later instead of a dict? -# -# 'type': (string) -# - 'S' (START condition) -# - 'Sr' (Repeated START) -# - 'AR' (Address, read) -# - 'AW' (Address, write) -# - 'DR' (Data, read) -# - 'DW' (Data, write) -# - 'P' (STOP condition) -# 'range': (tuple of 2 integers, the min/max samplenumber of this range) -# - (min, max) -# - min/max can also be identical. -# 'data': (actual data as integer ???) TODO: This can be very variable... -# 'ann': (string; additional annotations / comments) -# -# Example output: -# [{'type': 'S', 'range': (150, 160), 'data': None, 'ann': 'Foobar'}, -# {'type': 'AW', 'range': (200, 300), 'data': 0x50, 'ann': 'Slave 4'}, -# {'type': 'DW', 'range': (310, 370), 'data': 0x00, 'ann': 'Init cmd'}, -# {'type': 'AR', 'range': (500, 560), 'data': 0x50, 'ann': 'Get stat'}, -# {'type': 'DR', 'range': (580, 640), 'data': 0xfe, 'ann': 'OK'}, -# {'type': 'P', 'range': (650, 660), 'data': None, 'ann': None}] -# -# Possible other events: -# - Error event in case protocol looks broken: -# [{'type': 'ERROR', 'range': (min, max), -# 'data': TODO, 'ann': 'This is not a Microchip 24XX64 EEPROM'}, -# [{'type': 'ERROR', 'range': (min, max), -# 'data': TODO, 'ann': 'TODO'}, -# - TODO: Make list of possible errors accessible as metadata? -# # TODO: I2C address of slaves. # TODO: Handle multiple different I2C devices on same bus # -> we need to decode multiple protocols at the same time. -# TODO: range: Always contiguous? Splitted ranges? Multiple per event? -# # -# I2C input format: +# I2C protocol output format: # -# signals: -# [[id, channel, description], ...] # TODO +# The protocol output consists of a (Python) list of I2C "packets", each of +# which is of the form # -# Example: -# {'id': 'SCL', 'ch': 5, 'desc': 'Serial clock line'} -# {'id': 'SDA', 'ch': 7, 'desc': 'Serial data line'} -# ... +# [, , ] # -# {'inbuf': [...], -# 'signals': [{'SCL': }]} +# is one of: +# - 'START' (START condition) +# - 'START_REPEAT' (Repeated START) +# - 'ADDRESS_READ' (Slave address, read) +# - 'ADDRESS_WRITE' (Slave address, write) +# - 'DATA_READ' (Data, read) +# - 'DATA_WRITE' (Data, write) +# - 'STOP' (STOP condition) +# +# is the data or address byte associated with the ADDRESS_* and DATA_* +# command. For START, START_REPEAT and STOP, this is None. +# +# is either 'ACK' or 'NACK', but may also be None. # -import sigrokdecode - -# symbols for i2c decoders up the stack -START = 1 -START_REPEAT = 2 -STOP = 3 -ACK = 4 -NACK = 5 -ADDRESS_READ = 6 -ADDRESS_WRITE = 7 -DATA_READ = 8 -DATA_WRITE = 9 +import sigrokdecode as srd + +# Annotation feed formats +ANN_SHIFTED = 0 +ANN_SHIFTED_SHORT = 1 +ANN_RAW = 2 + +# Values are verbose and short annotation, respectively. +protocol = { + 'START': ['START', 'S'], + 'START_REPEAT': ['START REPEAT', 'Sr'], + 'STOP': ['STOP', 'P'], + 'ACK': ['ACK', 'A'], + 'NACK': ['NACK', 'N'], + 'ADDRESS_READ': ['ADDRESS READ', 'AR'], + 'ADDRESS_WRITE': ['ADDRESS WRITE', 'AW'], + 'DATA_READ': ['DATA READ', 'DR'], + 'DATA_WRITE': ['DATA WRITE', 'DW'], +} # States FIND_START = 0 FIND_ADDRESS = 1 FIND_DATA = 2 - -class Decoder(sigrokdecode.Decoder): +class Decoder(srd.Decoder): id = 'i2c' name = 'I2C' longname = 'Inter-Integrated Circuit (I2C) bus' @@ -163,10 +135,18 @@ class Decoder(sigrokdecode.Decoder): options = { 'address-space': ['Address space (in bits)', 7], } + annotations = [ + # ANN_SHIFTED + ['7-bit shifted hex', + 'Read/write bit shifted out from the 8-bit I2C slave address'], + # ANN_SHIFTED_SHORT + ['7-bit shifted hex (short)', + 'Read/write bit shifted out from the 8-bit I2C slave address'], + # ANN_RAW + ['Raw hex', 'Unaltered raw data'], + ] def __init__(self, **kwargs): - self.output_protocol = None - self.output_annotation = None self.samplecnt = 0 self.bitcount = 0 self.databyte = 0 @@ -178,39 +158,36 @@ class Decoder(sigrokdecode.Decoder): self.oldsda = None def start(self, metadata): - self.output_protocol = self.output_new(2) - self.output_annotation = self.output_new(1) + self.out_proto = self.add(srd.OUTPUT_PROTO, 'i2c') + self.out_ann = self.add(srd.OUTPUT_ANN, 'i2c') def report(self): pass def is_start_condition(self, scl, sda): - """START condition (S): SDA = falling, SCL = high""" + # START condition (S): SDA = falling, SCL = high if (self.oldsda == 1 and sda == 0) and scl == 1: return True return False def is_data_bit(self, scl, sda): - """Data sampling of receiver: SCL = rising""" + # Data sampling of receiver: SCL = rising if self.oldscl == 0 and scl == 1: return True return False def is_stop_condition(self, scl, sda): - """STOP condition (P): SDA = rising, SCL = high""" + # STOP condition (P): SDA = rising, SCL = high if (self.oldsda == 0 and sda == 1) and scl == 1: return True return False def found_start(self, scl, sda): - if self.is_repeat_start == 1: - out_proto = [ START_REPEAT ] - out_ann = [ "START REPEAT" ] - else: - out_proto = [ START ] - out_ann = [ "START" ] - self.put(self.output_protocol, out_proto) - self.put(self.output_annotation, out_ann) + cmd = 'START_REPEAT' if (self.is_repeat_start == 1) else 'START' + + self.put(self.out_proto, [cmd, None, None]) + self.put(self.out_ann, [ANN_SHIFTED, [protocol[cmd][0]]]) + self.put(self.out_ann, [ANN_SHIFTED_SHORT, [protocol[cmd][1]]]) self.state = FIND_ADDRESS self.bitcount = self.databyte = 0 @@ -218,10 +195,10 @@ class Decoder(sigrokdecode.Decoder): self.wr = -1 def found_address_or_data(self, scl, sda): - """Gather 8 bits of data plus the ACK/NACK bit.""" + # Gather 8 bits of data plus the ACK/NACK bit. if self.startsample == -1: - # TODO: should be samplenum, as received from the feed + # TODO: Should be samplenum, as received from the feed. self.startsample = self.samplecnt self.bitcount += 1 @@ -231,48 +208,48 @@ class Decoder(sigrokdecode.Decoder): # Return if we haven't collected all 8 + 1 bits, yet. if self.bitcount != 9: - return [] + return + + # Send raw output annotation before we start shifting out + # read/write and ack/nack bits. + self.put(self.out_ann, [ANN_RAW, ['0x%.2x' % self.databyte]]) # We received 8 address/data bits and the ACK/NACK bit. self.databyte >>= 1 # Shift out unwanted ACK/NACK bit here. if self.state == FIND_ADDRESS: - d = self.databyte & 0xfe # The READ/WRITE bit is only in address bytes, not data bytes. - self.wr = 1 if (self.databyte & 1) else 0 + self.wr = 0 if (self.databyte & 1) else 1 + d = self.databyte >> 1 elif self.state == FIND_DATA: d = self.databyte else: # TODO: Error? pass - out_proto = [] - out_ann = [] - # TODO: Simplify. + # Last bit that came in was the ACK/NACK bit (1 = NACK). + ack_bit = 'NACK' if (sda == 1) else 'ACK' + if self.state == FIND_ADDRESS and self.wr == 1: - cmd = ADDRESS_WRITE - ann = 'ADDRESS WRITE' + cmd = 'ADDRESS_WRITE' elif self.state == FIND_ADDRESS and self.wr == 0: - cmd = ADDRESS_READ - ann = 'ADDRESS READ' + cmd = 'ADDRESS_READ' elif self.state == FIND_DATA and self.wr == 1: - cmd = DATA_WRITE - ann = 'DATA WRITE' + cmd = 'DATA_WRITE' elif self.state == FIND_DATA and self.wr == 0: - cmd = DATA_READ - ann = 'DATA READ' - out_proto.append( [cmd, d] ) - out_ann.append( ["%s" % ann, "0x%02x" % d] ) - - if sda == 1: - out_proto.append( [NACK] ) - out_ann.append( ["NACK"] ) - else: - out_proto.append( [ACK] ) - out_ann.append( ["ACK"] ) - - self.put(self.output_protocol, out_proto) - self.put(self.output_annotation, out_ann) + cmd = 'DATA_READ' + + self.put(self.out_proto, [cmd, d, ack_bit]) + self.put(self.out_ann, [ANN_SHIFTED, [ + '%s' % protocol[cmd][0], + '0x%02x' % d, + '%s' % protocol[ack_bit][0]] + ]) + self.put(self.out_ann, [ANN_SHIFTED_SHORT, [ + '%s' % protocol[cmd][1], + '0x%02x' % d, + '%s' % protocol[ack_bit][1]] + ]) self.bitcount = self.databyte = 0 self.startsample = -1 @@ -285,15 +262,17 @@ class Decoder(sigrokdecode.Decoder): pass def found_stop(self, scl, sda): - self.put(self.output_protocol, [ STOP ]) - self.put(self.output_annotation, [ "STOP" ]) + self.put(self.out_proto, ['STOP', None, None]) + self.put(self.out_ann, [ANN_SHIFTED, [protocol['STOP'][0]]]) + self.put(self.out_ann, [ANN_SHIFTED_SHORT, [protocol['STOP'][1]]]) self.state = FIND_START self.is_repeat_start = 0 self.wr = -1 def put(self, output_id, data): - # inject sample range into the call up to sigrok + # Inject sample range into the call up to sigrok. + # TODO: 0-0 sample range for now. super(Decoder, self).put(0, 0, output_id, data) def decode(self, timeoffset, duration, data):