mirror of
https://github.com/DreamSourceLab/DSView.git
synced 2025-01-13 13:32:53 +08:00
51 lines
1.9 KiB
Python
Executable File
51 lines
1.9 KiB
Python
Executable File
##
|
|
## This file is part of the libsigrokdecode project.
|
|
##
|
|
## Copyright (C) 2015 Stefan Brüns <stefan.bruens@rwth-aachen.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
|
|
##
|
|
|
|
'''
|
|
This decoder stacks on top of the 'usb_packet' PD and decodes the USB
|
|
(low-speed and full-speed) transactions.
|
|
|
|
Transactions and requests are tracked per device address and endpoint.
|
|
|
|
Tracking of CONTROL requests is quite accurate, as these always start with
|
|
a SETUP token and are completed by an IN or OUT transaction, the status
|
|
packet. All transactions during the DATA stage are combined.
|
|
|
|
For BULK and INTERRUPT requests, each transaction starts with an IN or OUT
|
|
request, and is considered completed after the first transaction containing
|
|
data has been ACKed. Normally a request is only completed after a short or
|
|
zero length packet, but this would require knowledge about the max packet
|
|
size of an endpoint.
|
|
|
|
All INTERRUPT requests are treated as BULK requests, as on the link layer
|
|
both are identical.
|
|
|
|
The PCAP binary output contains 'SUBMIT' and 'COMPLETE' records. For
|
|
CONTROL request, the SUBMIT contains the SETUP request, the data is
|
|
either contained in the SUBMIT (Host-to-Device) or the COMPLETE
|
|
(Device-to-Host) record.
|
|
|
|
Details:
|
|
https://en.wikipedia.org/wiki/USB
|
|
http://www.usb.org/developers/docs/
|
|
'''
|
|
|
|
from .pd import Decoder
|