Rename usb_protocol to usb_packet.

[libsigrokdecode.git] / decoders / usb_packet / __init__.py

diff --git a/decoders/usb_packet/__init__.py b/decoders/usb_packet/__init__.py
new file mode 100644 (file)
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 *
+