srd: Drop 'usb' PD, replaced by two others.

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

diff --git a/decoders/usb/__init__.py b/decoders/usb/__init__.py
deleted file mode 100644 (file)
index 313c495..0000000
--- a/decoders/usb/__init__.py
+++ /dev/null
@@ -1,69 +0,0 @@
-##
-## This file is part of the sigrok 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) protocol decoder.
-
-Electrical/signalling layer (USB spec, chapter 7):
-
-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.
-
-Low-speed: The state where DP=1,DM=0 is K, the state DP=0,DM=1 is J.
-Full-speed: 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. A state SE1 is defined where DP=DM=1.
-
-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 1.5Mbit/s (low-speed) / 12Mbit/s (full-speed).
-
-The SE0 transmitted to signal an end-of-packet is two bit intervals long
-(low-speed: 1.25uS - 1.50uS, full-speed: 160ns - 175ns).
-
-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 .usb import *
-