+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2017 Marcus Comstedt <marcus@mc.pp.se>
+##
+## 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 = 2
+ id = 'iec'
+ name = 'IEC'
+ longname = 'Commodore bus'
+ desc = 'Commodore serial IEEE-488 (IEC) bus protocol.'
+ license = 'gplv2+'
+ inputs = ['logic']
+ outputs = ['gpib']
+ channels = (
+ {'id': 'data', 'name': 'DATA', 'desc': 'Data I/O'},
+ {'id': 'clk', 'name': 'CLK', 'desc': 'Clock'},
+ {'id': 'atn', 'name': 'ATN', 'desc': 'Attention'},
+ )
+ optional_channels = (
+ {'id': 'srq', 'name': 'SRQ', 'desc': 'Service request'},
+ )
+ annotations = (
+ ('items', 'Items'),
+ ('gpib', 'DAT/CMD'),
+ ('eoi', 'EOI'),
+ )
+ annotation_rows = (
+ ('bytes', 'Bytes', (0,)),
+ ('gpib', 'DAT/CMD', (1,)),
+ ('eoi', 'EOI', (2,)),
+ )
+
+ def __init__(self):
+ self.saved_ATN = False
+ self.saved_EOI = False
+ self.oldpins = None
+ self.ss_item = self.es_item = None
+ self.step = 0
+ self.bits = 0
+ self.numbits = 0
+
+ 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):
+ # Output the saved item.
+ dbyte = self.bits
+ dATN = self.saved_ATN
+ dEOI = self.saved_EOI
+ self.es_item = self.samplenum
+ self.putb([0, ['%02X' % dbyte]])
+
+ # Encode item byte to GPIB convention.
+ self.strgpib = ' '
+ if dATN: # ATN, decode commands.
+ # Note: Commands < 0x20 are not used on IEC bus.
+ 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)
+ if dbyte > 0x5f and dbyte < 0x70: # Channel reopen.
+ self.strgpib = 'R' + chr(dbyte - 0x30)
+ if dbyte > 0xdf and dbyte < 0xf0: # Channel close.
+ self.strgpib = 'C' + chr(dbyte - 0xb0)
+ if dbyte > 0xef: # Channel open.
+ self.strgpib = 'O' + chr(dbyte - 0xc0)
+ 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]])
+
+ def decode(self, ss, es, data):
+ for (self.samplenum, pins) in data:
+
+ # Ignore identical samples early on (for performance reasons).
+ if self.oldpins == pins:
+ continue
+
+ if pins[2] == 0 and self.oldpins[2] == 1:
+ # Falling edge on ATN, reset step.
+ self.step = 0
+
+ if self.step == 0:
+ if pins[0] == 0 and pins[1] == 1:
+ # Rising edge on CLK while DATA is low: Ready to send.
+ self.step = 1
+ elif self.step == 1:
+ if pins[0] == 1 and pins[1] == 1:
+ # Rising edge on DATA while CLK is high: Ready for data.
+ self.ss_item = self.samplenum
+ self.saved_ATN = not pins[2]
+ self.saved_EOI = False
+ self.bits = 0
+ self.numbits = 0
+ self.step = 2
+ elif pins[1] == 0:
+ # CLK low again, transfer aborted.
+ self.step = 0
+ elif self.step == 2:
+ if pins[0] == 0 and pins[1] == 1:
+ # DATA goes low while CLK is still high, EOI confirmed.
+ self.saved_EOI = True
+ elif pins[1] == 0:
+ self.step = 3
+ elif self.step == 3:
+ if pins[1] == 1 and self.oldpins[1] == 0:
+ # Rising edge on CLK; latch DATA.
+ self.bits |= pins[0] << self.numbits
+ elif pins[1] == 0 and self.oldpins[1] == 1:
+ # Falling edge on CLK; end of bit.
+ self.numbits += 1
+ if self.numbits == 8:
+ self.handle_bits()
+ self.step = 0
+
+ self.oldpins = pins
projects / libsigrokdecode.git / commitdiff