From 64c29e28e0efa184319f7831b3eca18c7f73f7d0 Mon Sep 17 00:00:00 2001 From: Uwe Hermann Date: Sun, 15 Jan 2012 15:36:01 +0100 Subject: srd: Each PD now has its own subdirectory. --- decoders/usb.py | 193 -------------------------------------------------------- 1 file changed, 193 deletions(-) delete mode 100644 decoders/usb.py (limited to 'decoders/usb.py') diff --git a/decoders/usb.py b/decoders/usb.py deleted file mode 100644 index 073fe01..0000000 --- a/decoders/usb.py +++ /dev/null @@ -1,193 +0,0 @@ -## -## This file is part of the sigrok project. -## -## Copyright (C) 2011 Gareth McMullin -## -## 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, write to the Free Software -## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA -## - -# -# USB Full-speed protocol decoder -# -# Full-speed USB signalling consists of two signal lines, both driven at 3.3V -# logic levels. The signals are DP (D+) and DM (D-), and normally operate in -# differential mode. -# The state where DP=1,DM=0 is J, the state DP=0,DM=1 is K. -# A state SE0 is defined where DP=DM=0. This common mode signal is used to -# signal a reset or end of packet. -# -# Data transmitted on the USB is encoded with NRZI. A transition from J to K -# or vice-versa indicates a logic 0, while no transition indicates a logic 1. -# If 6 ones are transmitted consecutively, a zero is inserted to force a -# transition. This is known as bit stuffing. Data is transferred at a rate -# of 12Mbit/s. The SE0 transmitted to signal an end-of-packet is two bit -# intervals long. -# -# Details: -# https://en.wikipedia.org/wiki/USB -# http://www.usb.org/developers/docs/ -# - -import sigrokdecode as srd - -# States -SE0, J, K, SE1 = 0, 1, 2, 3 - -# ... -syms = { - (0, 0): SE0, - (1, 0): J, - (0, 1): K, - (1, 1): SE1, -} - -# ... -pids = { - '10000111': 'OUT', # Tokens - '10010110': 'IN', - '10100101': 'SOF', - '10110100': 'SETUP', - '11000011': 'DATA0', # Data - '11010010': 'DATA1', - '01001011': 'ACK', # Handshake - '01011010': 'NAK', - '01111000': 'STALL', - '01101001': 'NYET', -} - -def bitstr_to_num(bitstr): - if not bitstr: - return 0 - l = list(bitstr) - l.reverse() - return int(''.join(l), 2) - -def packet_decode(packet): - sync = packet[:8] - pid = packet[8:16] - pid = pids.get(pid, pid) - - # Remove CRC. - if pid in ('OUT', 'IN', 'SOF', 'SETUP'): - data = packet[16:-5] - if pid == 'SOF': - data = str(bitstr_to_num(data)) - else: - dev = bitstr_to_num(data[:7]) - ep = bitstr_to_num(data[7:]) - data = 'DEV %d EP %d' % (dev, ep) - - elif pid in ('DATA0', 'DATA1'): - data = packet[16:-16] - tmp = '' - while data: - tmp += '%02x ' % bitstr_to_num(data[:8]) - data = data[8:] - data = tmp - else: - data = packet[16:] - - if sync != '00000001': - return 'SYNC INVALID!' - - return pid + ' ' + data - -class Decoder(srd.Decoder): - id = 'usb' - name = 'USB' - longname = 'Universal Serial Bus' - desc = 'Universal Serial Bus' - longdesc = '...longdesc...' - license = 'gplv2+' - inputs = ['logic'] - outputs = ['usb'] - probes = [ - {'id': 'dp', 'name': 'D+', 'desc': 'USB D+ signal'}, - {'id': 'dm', 'name': 'D-', 'desc': 'USB D- signal'}, - ] - options = {} - annotations = [ - ['TODO', 'TODO'] - ] - - def __init__(self): - pass - - def start(self, metadata): - self.rate = metadata['samplerate'] - - # self.out_proto = self.add(srd.OUTPUT_PROTO, 'usb') - self.out_ann = self.add(srd.OUTPUT_ANN, 'usb') - - if self.rate < 48000000: - raise Exception('Sample rate not sufficient for USB decoding') - - # Initialise decoder state. - self.sym = J - self.scount = 0 - self.packet = '' - - def decode(self, ss, es, data): - - # FIXME - # for (samplenum, (dp, dm, x, y, z, a)) in data: - for (samplenum, (dm, dp)) in data: - - self.scount += 1 - - sym = syms[dp, dm] - - # ... - if sym == self.sym: - continue - - if self.scount == 1: - # We ignore single sample width pulses. - # I sometimes get these with the OLS. - self.sym = sym - self.scount = 0 - continue - - # How many bits since the last transition? - if self.packet != '' or self.sym != J: - bitcount = int((self.scount - 1) * 12000000 / self.rate) - else: - bitcount = 0 - - if self.sym == SE0: - if bitcount == 1: - # End-Of-Packet (EOP) - self.put(0, 0, self.out_ann, - [0, [packet_decode(self.packet), self.packet]]) - else: - # Longer than EOP, assume reset. - self.put(0, 0, self.out_ann, [0, ['RESET']]) - self.scount = 0 - self.sym = sym - self.packet = '' - continue - - # Add bits to the packet string. - self.packet += '1' * bitcount - - # Handle bit stuffing. - if bitcount < 6 and sym != SE0: - self.packet += '0' - elif bitcount > 6: - self.put(0, 0, self.out_ann, [0, ['BIT STUFF ERROR']]) - - self.scount = 0 - self.sym = sym - -- cgit v1.2.3-70-g09d2