diff options
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/i2c.py | 74 |
1 files changed, 70 insertions, 4 deletions
diff --git a/scripts/i2c.py b/scripts/i2c.py index 5a41a58..c389c33 100644 --- a/scripts/i2c.py +++ b/scripts/i2c.py @@ -65,6 +65,66 @@ # 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: +# +# signals: +# [[id, channel, description], ...] # TODO +# +# Example: +# {'id': 'SCL', 'ch': 5, 'desc': 'Serial clock line'} +# {'id': 'SDA', 'ch': 7, 'desc': 'Serial data line'} +# ... +# +# {'inbuf': [...], +# 'signals': [{'SCL': }]} +# + def decode(inbuf): """I2C protocol decoder""" @@ -72,16 +132,22 @@ def decode(inbuf): inbuf = [ord(x) for x in inbuf] # FIXME: This should be passed in as metadata, not hardcoded here. - signals = (2, 5) - channels = 8 + metadata = { + 'numchannels': 8, + 'signals': { + 'scl': {'ch': 5, 'name': 'SCL', 'desc': 'Serial clock line'}, + 'sda': {'ch': 7, 'name': 'SDA' 'desc': 'Serial data line'}, + }, + } o = wr = ack = d = '' bitcount = data = 0 IDLE, START, ADDRESS, DATA = range(4) state = IDLE - # Get the bit number (and thus probe index) of the SCL/SDA signals. - scl_bit, sda_bit = signals + # 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] |