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##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2016 Rudolf Reuter <reuterru@arcor.de>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## 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, see <http://www.gnu.org/licenses/>.
##
import sigrokdecode as srd
class Decoder(srd.Decoder):
api_version = 3
id = 'gpib'
name = 'GPIB'
longname = 'General Purpose Interface Bus'
desc = 'IEEE-488 GPIB / HPIB protocol.'
license = 'gplv2+'
inputs = ['logic']
outputs = ['gpib']
tags = ['PC']
channels = (
{'id': 'dio1' , 'name': 'DIO1', 'desc': 'Data I/O bit 1'},
{'id': 'dio2' , 'name': 'DIO2', 'desc': 'Data I/O bit 2'},
{'id': 'dio3' , 'name': 'DIO3', 'desc': 'Data I/O bit 3'},
{'id': 'dio4' , 'name': 'DIO4', 'desc': 'Data I/O bit 4'},
{'id': 'dio5' , 'name': 'DIO5', 'desc': 'Data I/O bit 5'},
{'id': 'dio6' , 'name': 'DIO6', 'desc': 'Data I/O bit 6'},
{'id': 'dio7' , 'name': 'DIO7', 'desc': 'Data I/O bit 7'},
{'id': 'dio8' , 'name': 'DIO8', 'desc': 'Data I/O bit 8'},
{'id': 'eoi', 'name': 'EOI', 'desc': 'End or identify'},
{'id': 'dav', 'name': 'DAV', 'desc': 'Data valid'},
{'id': 'nrfd', 'name': 'NRFD', 'desc': 'Not ready for data'},
{'id': 'ndac', 'name': 'NDAC', 'desc': 'Not data accepted'},
{'id': 'ifc', 'name': 'IFC', 'desc': 'Interface clear'},
{'id': 'srq', 'name': 'SRQ', 'desc': 'Service request'},
{'id': 'atn', 'name': 'ATN', 'desc': 'Attention'},
{'id': 'ren', 'name': 'REN', 'desc': 'Remote enable'},
)
options = (
{'id': 'sample_total', 'desc': 'Total number of samples', 'default': 0},
)
annotations = (
('items', 'Items'),
('gpib', 'DAT/CMD'),
('eoi', 'EOI'),
)
annotation_rows = (
('bytes', 'Bytes', (0,)),
('gpib', 'DAT/CMD', (1,)),
('eoi', 'EOI', (2,)),
)
def __init__(self):
self.reset()
def reset(self):
self.items = []
self.itemcount = 0
self.saved_item = None
self.saved_ATN = False
self.saved_EOI = False
self.samplenum = 0
self.ss_item = self.es_item = None
self.first = True
def start(self):
self.out_ann = self.register(srd.OUTPUT_ANN)
def putb(self, data):
self.put(self.ss_item, self.es_item, self.out_ann, data)
def handle_bits(self, datapins):
dbyte = 0x20
dATN = False
item2 = False
dEOI = False
item3 = False
# If this is the first item in a word, save its sample number.
if self.itemcount == 0:
self.ss_word = self.samplenum
# Get the bits for this item.
item = 0
for i in range(8):
item |= datapins[i] << i
item = item ^ 0xff # Invert data byte.
self.items.append(item)
self.itemcount += 1
if datapins[14] == 0:
item2 = True
if datapins[8] == 0:
item3 = True
if self.first:
# Save the start sample and item for later (no output yet).
self.ss_item = self.samplenum
self.first = False
self.saved_item = item
self.saved_ATN = item2
self.saved_EOI = item3
else:
# Output the saved item.
dbyte = self.saved_item
dATN = self.saved_ATN
dEOI = self.saved_EOI
self.es_item = self.samplenum
self.putb([0, ['%02X' % self.saved_item]])
# Encode item byte to GPIB convention.
self.strgpib = ' '
if dATN: # ATN, decode commands.
if dbyte == 0x01: self.strgpib = 'GTL'
if dbyte == 0x04: self.strgpib = 'SDC'
if dbyte == 0x05: self.strgpib = 'PPC'
if dbyte == 0x08: self.strgpib = 'GET'
if dbyte == 0x09: self.strgpib = 'TCT'
if dbyte == 0x11: self.strgpib = 'LLO'
if dbyte == 0x14: self.strgpib = 'DCL'
if dbyte == 0x15: self.strgpib = 'PPU'
if dbyte == 0x18: self.strgpib = 'SPE'
if dbyte == 0x19: self.strgpib = 'SPD'
if dbyte == 0x3f: self.strgpib = 'UNL'
if dbyte == 0x5f: self.strgpib = 'UNT'
if dbyte > 0x1f and dbyte < 0x3f: # Address Listener.
self.strgpib = 'L' + chr(dbyte + 0x10)
if dbyte > 0x3f and dbyte < 0x5f: # Address Talker
self.strgpib = 'T' + chr(dbyte - 0x10)
else:
if dbyte > 0x1f and dbyte < 0x7f:
self.strgpib = chr(dbyte)
if dbyte == 0x0a:
self.strgpib = 'LF'
if dbyte == 0x0d:
self.strgpib = 'CR'
self.putb([1, [self.strgpib]])
self.strEOI = ' '
if dEOI:
self.strEOI = 'EOI'
self.putb([2, [self.strEOI]])
self.ss_item = self.samplenum
self.saved_item = item
self.saved_ATN = item2
self.saved_EOI = item3
if self.itemcount < 16:
return
self.itemcount, self.items = 0, []
def decode(self):
# Inspect samples at falling edge of DAV. But make sure to also
# start inspection when the capture happens to start with low
# DAV level. Optionally enforce processing when a user specified
# sample number was reached.
waitcond = [{9: 'l'}]
lsn = self.options['sample_total']
if lsn:
waitcond.append({'skip': lsn})
while True:
if lsn:
waitcond[1]['skip'] = lsn - self.samplenum - 1
pins = self.wait(waitcond)
self.handle_bits(pins)
waitcond[0][9] = 'f'
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