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-rw-r--r--decoders/i2c.py232
1 files changed, 115 insertions, 117 deletions
diff --git a/decoders/i2c.py b/decoders/i2c.py
index f2b0c2d..874e735 100644
--- a/decoders/i2c.py
+++ b/decoders/i2c.py
@@ -99,9 +99,9 @@
# 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'},
+# 'data': TODO, 'ann': 'This is not a Microchip 24XX64 EEPROM'},
# [{'type': 'ERROR', 'range': (min, max),
-# 'data': TODO, 'ann': 'TODO'},
+# 'data': TODO, 'ann': 'TODO'},
# - TODO: Make list of possible errors accessible as metadata?
#
# TODO: I2C address of slaves.
@@ -126,145 +126,143 @@
#
def decode(l):
- print(l)
- sigrok.put(l)
-
-
+ print(l)
+ sigrok.put(l)
def decode2(inbuf):
- """I2C protocol decoder"""
+ """I2C protocol decoder"""
- # FIXME: Get the data in the correct format in the first place.
- inbuf = [ord(x) for x in inbuf]
+ # FIXME: Get the data in the correct format in the first place.
+ inbuf = [ord(x) for x in inbuf]
- # FIXME: This should be passed in as metadata, not hardcoded here.
- metadata = {
- 'numchannels': 8,
- 'signals': {
- 'scl': {'ch': 5, 'name': 'SCL', 'desc': 'Serial clock line'},
- 'sda': {'ch': 7, 'name': 'SDA', 'desc': 'Serial data line'},
- },
- }
+ # FIXME: This should be passed in as metadata, not hardcoded here.
+ metadata = {
+ 'numchannels': 8,
+ 'signals': {
+ 'scl': {'ch': 5, 'name': 'SCL', 'desc': 'Serial clock line'},
+ 'sda': {'ch': 7, 'name': 'SDA', 'desc': 'Serial data line'},
+ },
+ }
- out = []
- o = ack = d = ''
- bitcount = data = 0
- wr = startsample = -1
- IDLE, START, ADDRESS, DATA = range(4)
- state = IDLE
+ out = []
+ o = ack = d = ''
+ bitcount = data = 0
+ wr = startsample = -1
+ IDLE, START, ADDRESS, DATA = range(4)
+ state = IDLE
- # Get the channel/probe number of the SCL/SDA signals.
- scl_bit = metadata['signals']['scl']['ch']
- sda_bit = metadata['signals']['sda']['ch']
+ # Get the channel/probe number of the SCL/SDA signals.
+ scl_bit = metadata['signals']['scl']['ch']
+ sda_bit = metadata['signals']['sda']['ch']
- # Get SCL/SDA bit values (0/1 for low/high) of the first sample.
- s = inbuf[0]
- oldscl = (s & (1 << scl_bit)) >> scl_bit
- oldsda = (s & (1 << sda_bit)) >> sda_bit
+ # Get SCL/SDA bit values (0/1 for low/high) of the first sample.
+ s = inbuf[0]
+ oldscl = (s & (1 << scl_bit)) >> scl_bit
+ oldsda = (s & (1 << sda_bit)) >> sda_bit
- # Loop over all samples.
- # TODO: Handle LAs with more/less than 8 channels.
- for samplenum, s in enumerate(inbuf[1:]): # We skip the first byte...
- # Get SCL/SDA bit values (0/1 for low/high).
- scl = (s & (1 << scl_bit)) >> scl_bit
- sda = (s & (1 << sda_bit)) >> sda_bit
+ # Loop over all samples.
+ # TODO: Handle LAs with more/less than 8 channels.
+ for samplenum, s in enumerate(inbuf[1:]): # We skip the first byte...
+ # Get SCL/SDA bit values (0/1 for low/high).
+ scl = (s & (1 << scl_bit)) >> scl_bit
+ sda = (s & (1 << sda_bit)) >> sda_bit
- # TODO: Wait until the bus is idle (SDA = SCL = 1) first?
+ # TODO: Wait until the bus is idle (SDA = SCL = 1) first?
- # START condition (S): SDA = falling, SCL = high
- if (oldsda == 1 and sda == 0) and scl == 1:
- o = {'type': 'S', 'range': (samplenum, samplenum),
- 'data': None, 'ann': None},
- out.append(o)
- state = ADDRESS
- bitcount = data = 0
+ # START condition (S): SDA = falling, SCL = high
+ if (oldsda == 1 and sda == 0) and scl == 1:
+ o = {'type': 'S', 'range': (samplenum, samplenum),
+ 'data': None, 'ann': None},
+ out.append(o)
+ state = ADDRESS
+ bitcount = data = 0
- # Data latching by transmitter: SCL = low
- elif (scl == 0):
- pass # TODO
+ # Data latching by transmitter: SCL = low
+ elif (scl == 0):
+ pass # TODO
- # Data sampling of receiver: SCL = rising
- elif (oldscl == 0 and scl == 1):
- if startsample == -1:
- startsample = samplenum
- bitcount += 1
+ # Data sampling of receiver: SCL = rising
+ elif (oldscl == 0 and scl == 1):
+ if startsample == -1:
+ startsample = samplenum
+ bitcount += 1
- # out.append("%d\t\tRECEIVED BIT %d: %d\n" % \
- # (samplenum, 8 - bitcount, sda))
+ # out.append("%d\t\tRECEIVED BIT %d: %d\n" % \
+ # (samplenum, 8 - bitcount, sda))
- # Address and data are transmitted MSB-first.
- data <<= 1
- data |= sda
+ # Address and data are transmitted MSB-first.
+ data <<= 1
+ data |= sda
- if bitcount != 9:
- continue
+ if bitcount != 9:
+ continue
- # We received 8 address/data bits and the ACK/NACK bit.
- data >>= 1 # Shift out unwanted ACK/NACK bit here.
- ack = (sda == 1) and 'N' or 'A'
- d = (state == ADDRESS) and (data & 0xfe) or data
- if state == ADDRESS:
- wr = (data & 1) and 1 or 0
- state = DATA
- o = {'type': state,
- 'range': (startsample, samplenum - 1),
- 'data': d, 'ann': None}
- if state == ADDRESS and wr == 1:
- o['type'] = 'AW'
- elif state == ADDRESS and wr == 0:
- o['type'] = 'AR'
- elif state == DATA and wr == 1:
- o['type'] = 'DW'
- elif state == DATA and wr == 0:
- o['type'] = 'DR'
- out.append(o)
- o = {'type': ack, 'range': (samplenum, samplenum),
- 'data': None, 'ann': None}
- out.append(o)
- bitcount = data = startsample = 0
- startsample = -1
+ # We received 8 address/data bits and the ACK/NACK bit.
+ data >>= 1 # Shift out unwanted ACK/NACK bit here.
+ ack = (sda == 1) and 'N' or 'A'
+ d = (state == ADDRESS) and (data & 0xfe) or data
+ if state == ADDRESS:
+ wr = (data & 1) and 1 or 0
+ state = DATA
+ o = {'type': state,
+ 'range': (startsample, samplenum - 1),
+ 'data': d, 'ann': None}
+ if state == ADDRESS and wr == 1:
+ o['type'] = 'AW'
+ elif state == ADDRESS and wr == 0:
+ o['type'] = 'AR'
+ elif state == DATA and wr == 1:
+ o['type'] = 'DW'
+ elif state == DATA and wr == 0:
+ o['type'] = 'DR'
+ out.append(o)
+ o = {'type': ack, 'range': (samplenum, samplenum),
+ 'data': None, 'ann': None}
+ out.append(o)
+ bitcount = data = startsample = 0
+ startsample = -1
- # STOP condition (P): SDA = rising, SCL = high
- elif (oldsda == 0 and sda == 1) and scl == 1:
- o = {'type': 'P', 'range': (samplenum, samplenum),
- 'data': None, 'ann': None},
- out.append(o)
- state = IDLE
- wr = -1
+ # STOP condition (P): SDA = rising, SCL = high
+ elif (oldsda == 0 and sda == 1) and scl == 1:
+ o = {'type': 'P', 'range': (samplenum, samplenum),
+ 'data': None, 'ann': None},
+ out.append(o)
+ state = IDLE
+ wr = -1
- # Save current SDA/SCL values for the next round.
- oldscl = scl
- oldsda = sda
+ # Save current SDA/SCL values for the next round.
+ oldscl = scl
+ oldsda = sda
- # FIXME: Just for testing...
- return str(out)
+ # FIXME: Just for testing...
+ return str(out)
register = {
- 'id': 'i2c',
- 'name': 'I2C',
- 'longname': 'Inter-Integrated Circuit (I2C) bus',
- 'desc': 'I2C is a two-wire, multi-master, serial bus.',
- 'longdesc': '...',
- 'author': 'Uwe Hermann',
- 'email': 'uwe@hermann-uwe.de',
- 'license': 'gplv2+',
- 'in': ['logic'],
- 'out': ['i2c'],
- 'probes': [
- ['scl', 'Serial clock line'],
- ['sda', 'Serial data line'],
- ],
- 'options': {
- 'address-space': ['Address space (in bits)', 7],
- },
- # 'start': start,
- # 'report': report,
+ 'id': 'i2c',
+ 'name': 'I2C',
+ 'longname': 'Inter-Integrated Circuit (I2C) bus',
+ 'desc': 'I2C is a two-wire, multi-master, serial bus.',
+ 'longdesc': '...',
+ 'author': 'Uwe Hermann',
+ 'email': 'uwe@hermann-uwe.de',
+ 'license': 'gplv2+',
+ 'in': ['logic'],
+ 'out': ['i2c'],
+ 'probes': [
+ ['scl', 'Serial clock line'],
+ ['sda', 'Serial data line'],
+ ],
+ 'options': {
+ 'address-space': ['Address space (in bits)', 7],
+ },
+ # 'start': start,
+ # 'report': report,
}
# Use psyco (if available) as it results in huge performance improvements.
try:
- import psyco
- psyco.bind(decode)
+ import psyco
+ psyco.bind(decode)
except ImportError:
- pass
+ pass
generated by cgit v1.2.3-70-g09d2 (git 2.47.0) at 2024-11-15 15:22:46 +0000