# 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)
-#
# TODO: I2C address of slaves.
# TODO: Handle multiple different I2C devices on same bus
# -> we need to decode multiple protocols at the same time.
-#
#
-# I2C input format:
+# I2C protocol output format:
+#
+# The protocol output consists of a (Python) list of I2C "packets", each of
+# which is of the form
+#
+# [ _i2c_command_, _data_, _ack_bit_ ]
#
-# signals:
-# [[id, channel, description], ...] # TODO
+# _i2c_command_ is one of:
+# - 'START' (START condition)
+# - 'START_REPEAT' (Repeated START)
+# - 'ADDRESS_READ' (Address, read)
+# - 'ADDRESS_WRITE' (Address, write)
+# - 'DATA_READ' (Data, read)
+# - 'DATA_WRITE' (Data, write)
+# - 'STOP' (STOP condition)
#
-# Example:
-# {'id': 'SCL', 'ch': 5, 'desc': 'Serial clock line'}
-# {'id': 'SDA', 'ch': 7, 'desc': 'Serial data line'}
-# ...
+# _data_ is the data or address byte associated with the ADDRESS_* and DATA_*
+# command. For START, START_REPEAT and STOP, this is None.
+#
+# _ack_bit_ is either 'ACK' or 'NACK', but may also be None.
#
-# {'inbuf': [...],
-# 'signals': [{'SCL': }]}
#
-import sigrokdecode
+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 = {
'DATA_READ': ['DATA READ', 'DR'],
'DATA_WRITE': ['DATA WRITE', 'DW'],
}
-# export protocol keys as symbols for i2c decoders up the stack
-EXPORT = [ protocol.keys() ]
# States
FIND_START = 0
FIND_ADDRESS = 1
FIND_DATA = 2
-# annotation feed formats
-ANN_SHIFTED = 0
-ANN_SHIFTED_SHORT = 1
-ANN_RAW = 2
-
-class Decoder(sigrokdecode.Decoder):
+class Decoder(srd.Decoder):
id = 'i2c'
name = 'I2C'
longname = 'Inter-Integrated Circuit (I2C) bus'
options = {
'address-space': ['Address space (in bits)', 7],
}
- annotation = [
+ annotations = [
# ANN_SHIFTED
["7-bit shifted hex",
"Read/Write bit shifted out from the 8-bit i2c slave address"],
]
def __init__(self, **kwargs):
- self.output_protocol = None
- self.output_annotation = None
self.samplecnt = 0
self.bitcount = 0
self.databyte = 0
self.oldsda = None
def start(self, metadata):
- self.output_protocol = self.output_new(sigrokdecode.SRD_OUTPUT_PROTOCOL, 'i2c')
- self.output_annotation = self.output_new(sigrokdecode.SRD_OUTPUT_ANNOTATION, 'i2c')
+ self.out_proto = self.add(srd.SRD_OUTPUT_PROTO, 'i2c')
+ self.out_ann = self.add(srd.SRD_OUTPUT_ANN, 'i2c')
def report(self):
pass
cmd = 'START_REPEAT'
else:
cmd = 'START'
- self.put(self.output_protocol, [ cmd ])
- self.put(self.output_annotation, [ ANN_SHIFTED, [protocol[cmd][0]] ])
- self.put(self.output_annotation, [ ANN_SHIFTED_SHORT, [protocol[cmd][1]] ])
+ 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
# send raw output annotation before we start shifting out
# read/write and ack/nack bits
- self.put(self.output_annotation, [ANN_RAW, ["0x%.2x" % self.databyte]])
+ 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
+ if self.databyte & 1:
+ self.wr = 0
+ else:
+ self.wr = 1
+ d = self.databyte >> 1
elif self.state == FIND_DATA:
d = self.databyte
else:
cmd = 'DATA_WRITE'
elif self.state == FIND_DATA and self.wr == 0:
cmd = 'DATA_READ'
- self.put(self.output_protocol, [ [cmd, d], [ack_bit] ] )
- self.put(self.output_annotation, [ANN_SHIFTED, [
+ 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.output_annotation, [ANN_SHIFTED_SHORT, [
+ self.put(self.out_ann, [ANN_SHIFTED_SHORT, [
"%s" % protocol[cmd][1],
"0x%02x" % d,
"%s" % protocol[ack_bit][1]]
pass
def found_stop(self, scl, sda):
- self.put(self.output_protocol, [ 'STOP' ])
- self.put(self.output_annotation, [ ANN_SHIFTED, [protocol['STOP'][0]] ])
- self.put(self.output_annotation, [ ANN_SHIFTED_SHORT, [protocol['STOP'][1]] ])
+ 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
projects / libsigrokdecode.git / blobdiff