## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
-## along with this program; if not, write to the Free Software
-## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
##
import sigrokdecode as srd
+class SamplerateError(Exception):
+ pass
+
class Decoder(srd.Decoder):
- api_version = 1
+ api_version = 3
id = 'onewire_link'
name = '1-Wire link layer'
longname = '1-Wire serial communication bus (link layer)'
def putrs(self, data):
self.put(self.rise, self.samplenum, self.out_ann, data)
- def __init__(self, **kwargs):
+ def __init__(self):
self.samplerate = None
- self.samplenum = 0
self.state = 'WAIT FOR FALLING EDGE'
self.present = 0
self.bit = 0
self.out_python = self.register(srd.OUTPUT_PYTHON)
self.out_ann = self.register(srd.OUTPUT_ANN)
- def metadata(self, key, value):
- if key != srd.SRD_CONF_SAMPLERATE:
- return
- self.samplerate = value
+ self.initial_pins = [1, 1]
+ def checks(self):
# Check if samplerate is appropriate.
if self.options['overdrive'] == 'yes':
if self.samplerate < 2000000:
if self.samplerate < 400000:
self.putm([1, ['Sampling rate is too low. Must be above ' +
'400kHz for proper normal mode decoding.']])
- elif (self.samplerate < 1000000):
+ elif self.samplerate < 1000000:
self.putm([1, ['Sampling rate is suggested to be above ' +
'1MHz for proper normal mode decoding.']])
- # The default 1-Wire time base is 30us. This is used to calculate
- # sampling times.
- samplerate = float(self.samplerate)
-
- x = float(self.options['cnt_normal_bit']) / 1000000.0
- self.cnt_normal_bit = int(samplerate * x) - 1
- x = float(self.options['cnt_normal_slot']) / 1000000.0
- self.cnt_normal_slot = int(samplerate * x) - 1
- x = float(self.options['cnt_normal_presence']) / 1000000.0
- self.cnt_normal_presence = int(samplerate * x) - 1
- x = float(self.options['cnt_normal_reset']) / 1000000.0
- self.cnt_normal_reset = int(samplerate * x) - 1
- x = float(self.options['cnt_overdrive_bit']) / 1000000.0
- self.cnt_overdrive_bit = int(samplerate * x) - 1
- x = float(self.options['cnt_overdrive_slot']) / 1000000.0
- self.cnt_overdrive_slot = int(samplerate * x) - 1
- x = float(self.options['cnt_overdrive_presence']) / 1000000.0
- self.cnt_overdrive_presence = int(samplerate * x) - 1
- x = float(self.options['cnt_overdrive_reset']) / 1000000.0
- self.cnt_overdrive_reset = int(samplerate * x) - 1
-
- # Organize values into lists.
- self.cnt_bit = [self.cnt_normal_bit, self.cnt_overdrive_bit]
- self.cnt_presence = [self.cnt_normal_presence, self.cnt_overdrive_presence]
- self.cnt_reset = [self.cnt_normal_reset, self.cnt_overdrive_reset]
- self.cnt_slot = [self.cnt_normal_slot, self.cnt_overdrive_slot]
-
# Check if sample times are in the allowed range.
time_min = float(self.cnt_normal_bit) / self.samplerate
if (time_min < 0.0000073) or (time_max > 0.000010):
self.putm([1, ['The overdrive mode presence sample time interval ' +
'(%2.1fus-%2.1fus) should be inside (7.3us, 10.0us).'
- % (time_min*1000000, time_max*1000000)]])
+ % (time_min * 1000000, time_max * 1000000)]])
- def decode(self, ss, es, data):
- if self.samplerate is None:
- raise Exception("Cannot decode without samplerate.")
- for (self.samplenum, (owr, pwr)) in data:
+
+ def metadata(self, key, value):
+ if key != srd.SRD_CONF_SAMPLERATE:
+ return
+ self.samplerate = value
+
+ # The default 1-Wire time base is 30us. This is used to calculate
+ # sampling times.
+ samplerate = float(self.samplerate)
+
+ x = float(self.options['cnt_normal_bit']) / 1000000.0
+ self.cnt_normal_bit = int(samplerate * x) - 1
+ x = float(self.options['cnt_normal_slot']) / 1000000.0
+ self.cnt_normal_slot = int(samplerate * x) - 1
+ x = float(self.options['cnt_normal_presence']) / 1000000.0
+ self.cnt_normal_presence = int(samplerate * x) - 1
+ x = float(self.options['cnt_normal_reset']) / 1000000.0
+ self.cnt_normal_reset = int(samplerate * x) - 1
+ x = float(self.options['cnt_overdrive_bit']) / 1000000.0
+ self.cnt_overdrive_bit = int(samplerate * x) - 1
+ x = float(self.options['cnt_overdrive_slot']) / 1000000.0
+ self.cnt_overdrive_slot = int(samplerate * x) - 1
+ x = float(self.options['cnt_overdrive_presence']) / 1000000.0
+ self.cnt_overdrive_presence = int(samplerate * x) - 1
+ x = float(self.options['cnt_overdrive_reset']) / 1000000.0
+ self.cnt_overdrive_reset = int(samplerate * x) - 1
+
+ # Organize values into lists.
+ self.cnt_bit = [self.cnt_normal_bit, self.cnt_overdrive_bit]
+ self.cnt_presence = [self.cnt_normal_presence, self.cnt_overdrive_presence]
+ self.cnt_reset = [self.cnt_normal_reset, self.cnt_overdrive_reset]
+ self.cnt_slot = [self.cnt_normal_slot, self.cnt_overdrive_slot]
+
+ def decode(self):
+ if not self.samplerate:
+ raise SamplerateError('Cannot decode without samplerate.')
+ self.checks()
+ while True:
# State machine.
if self.state == 'WAIT FOR FALLING EDGE':
- # The start of a cycle is a falling edge.
- if owr != 0:
- continue
+ # The start of a cycle is a falling edge on OWR.
+ self.wait({0: 'f'})
# Save the sample number for the falling edge.
self.fall = self.samplenum
- # Go to waiting for sample time.
self.state = 'WAIT FOR DATA SAMPLE'
elif self.state == 'WAIT FOR DATA SAMPLE':
# Sample data bit.
- t = self.samplenum - self.fall
- if t == self.cnt_bit[self.overdrive]:
- self.bit = owr
- self.state = 'WAIT FOR DATA SLOT END'
+ t = self.fall + self.cnt_bit[self.overdrive]
+ self.bit, pwr = self.wait({'skip': t - self.samplenum})
+ self.state = 'WAIT FOR DATA SLOT END'
elif self.state == 'WAIT FOR DATA SLOT END':
# A data slot ends in a recovery period, otherwise, this is
# probably a reset.
- t = self.samplenum - self.fall
- if t != self.cnt_slot[self.overdrive]:
- continue
+ t = self.fall + self.cnt_slot[self.overdrive]
+ owr, pwr = self.wait({'skip': t - self.samplenum})
if owr == 0:
# This seems to be a reset slot, wait for its end.
self.state = 'WAIT FOR FALLING EDGE'
elif self.state == 'WAIT FOR RISING EDGE':
# The end of a cycle is a rising edge.
- if owr != 1:
- continue
+ self.wait({0: 'r'})
# Check if this was a reset cycle.
t = self.samplenum - self.fall
# Save the sample number for the rising edge.
self.rise = self.samplenum
self.putfr([2, ['Reset', 'Rst', 'R']])
- self.state = "WAIT FOR PRESENCE DETECT"
+ self.state = 'WAIT FOR PRESENCE DETECT'
# Otherwise this is assumed to be a data bit.
else:
- self.state = "WAIT FOR FALLING EDGE"
+ self.state = 'WAIT FOR FALLING EDGE'
elif self.state == 'WAIT FOR PRESENCE DETECT':
# Sample presence status.
- t = self.samplenum - self.rise
- if t == self.cnt_presence[self.overdrive]:
- self.present = owr
- self.state = 'WAIT FOR RESET SLOT END'
+ t = self.rise + self.cnt_presence[self.overdrive]
+ owr, pwr = self.wait({'skip': t - self.samplenum})
+ self.present = owr
+ self.state = 'WAIT FOR RESET SLOT END'
elif self.state == 'WAIT FOR RESET SLOT END':
# A reset slot ends in a long recovery period.
- t = self.samplenum - self.rise
- if t != self.cnt_reset[self.overdrive]:
- continue
+ t = self.rise + self.cnt_reset[self.overdrive]
+ owr, pwr = self.wait({'skip': t - self.samplenum})
if owr == 0:
# This seems to be a reset slot, wait for its end.
# Wait for next slot.
self.state = 'WAIT FOR FALLING EDGE'
- else:
- raise Exception('Invalid state: %s' % self.state)
projects / libsigrokdecode.git / blobdiff