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Diffstat (limited to 'decoders/usb_packet/__init__.py')
| -rw-r--r-- | decoders/usb_packet/__init__.py | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/decoders/usb_packet/__init__.py b/decoders/usb_packet/__init__.py new file mode 100644 index 0000000..555dc7f --- /dev/null +++ b/decoders/usb_packet/__init__.py @@ -0,0 +1,47 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.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, write to the Free Software +## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +## + +''' +USB (low-speed and full-speed) packet protocol decoder. + +Protocol layer (USB spec, chapter 8): + +Bit/byte ordering: Bits are sent onto the bus LSB-first. Multibyte fields +are transmitted in little-endian order (i.e., LSB to MSB). + +SYNC field: All packets begin with a SYNC field (8 bits). + +Packet field format: Packets start with an SOP (Start Of Packet) delimiter +that is part of the SYNC field, and end with an EOP (End Of Packet). + +PID: A PID (packet identifier) follows the SYNC field of every packet. A PID +consists of a 4-bit packet type field, and a 4 bit check field. +The check field is the one's complement of the packet type field. + +Protocol output format: +TODO + +Details: +https://en.wikipedia.org/wiki/USB +http://www.usb.org/developers/docs/ +''' + +from .pd import * + |