Packet-Master
USB12
USB
Bus Analyser
Introduction
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The
Packet-Master USB12 is a Hardware USB Bus Analyser, intended
for development of Low and Full Speed USB devices and
hubs etc. It comes complete with our Windows application
Graphic USB for capturing and displaying every detail
of the data interactions on a USB link.
Download a PDF version of this Data Sheet
Download
Packet-Master USB12 Manual (390 Kbytes)
Download
the GraphicUSB Application (V1.08 - 10 Nov 2006 - 1.8
Mbytes)
What's
in the new version?
Buy
or Rent Now
USB
Made Simple
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Take
Control of your USB Development
Chapter
9 of the USB Specification details some seventeen
Standard Device Requests which must be correctly
implemented in any USB device, in order for the
device to be successfully enumerated by the host
controller.
When
developing a USB-based device it is a major undertaking
to implement the basic Chapter 9 Framework correctly
as enumeration will simply fail for any number of
reasons involving incorrect responses to the requests.
There
is no substitute for a USB bus-analyser for revealing
the smallest details of the packet transfers which
takes place on the bus. Software based analysers
can only ever give you a partial picture of what
is going on, usually not reporting at all the packets
with the errors.
The
Packet-Master USB12 connects passively between a
host computer and the USB device, and captures all
USB activity without influencing the link.
Benefits
of Packet-Master USB12
Save
Development Time
The
Packet-Master USB12 will provide you with exact
information showing you at which point a device
under development is failing. It will save you weeks
of wasted development time. In many cases you will
find that the error you are looking for is highlighted
on the Graphic USB display in a distinctive colour.
Simple
Connection
The
USB12 connects passively between a host computer
and the USB device, and captures all USB activity
without influencing the link. So you can be sure
that you are seeing exactly what really happens.
All the important timings are displayed.
Understand
USB
When
it comes to the USB protocol, a picture is worth
a thousand words. The graphical display of Graphic
USB immediately provides deeper understanding of
the data transfers and their related timings. By
examining a working device, you will learn more
in a few minutes than from hours of reading the
specifications. (Specifications are essential too,
but easier to understand when you have a picture
in your mind.)
Understand
Host Command Sequences
There
is no specification as to the sequence of commands
which a device may expect from a host. Some command
sequences can be very surprising to the starting-out
developer. The Packet-Master USB12 will allow you
to examine the sequences for any Operating System
/ Host Controller combination of your choice. This
will allow you to reveal any false assumptions you
may be making that a particular enumeration sequence
is standardised.
(As a device developer, just remember that the device
should make no assumptions about enumeration sequences,
but simply respond correctly to any request it receives.)
Examine
Working Devices
A
great benefit available from the Packet-Master USB12
is that it allows you to examine exactly what transactions
occur in a working device, perhaps manufactured
by a third party. This may reveal your own bad assumptions
about how a protocol works, or may show you how
many devices on the market do not obey the rules.
Some operating systems have work-arounds for certain
common protocol errors, and you may discover some
of these first-hand.
Specifications often contain ambiguities. For example,
without seeing it for yourself, you might not have
realised that there have been two different ways
of encoding the version number (bcdUSB) for USB
1.1. Operating systems appear to take the pragmatic
approach of accepting either.
Fine-tune
Performance
Much
of the effort in developing a new device will go
into achieving the throughput required. There is
no substitute for seeing the transactions attempted
by the host, together with the device's response
to them. Armed with this valuable information you
will be in the best position to be able to fine-tune
your device's performance.
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Hardware
Features
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Front
View
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- Power
Indicator
- Activity
indicator shows presence of data exchanges
- Integral
Capture Start and Stop buttons and Capture Indicator
- USB
through-connectors for device under test
- Analyses
Low Speed (1.5 Mbit/s), Full Speed (12 Mbit/s)
or a mixture of both
- Automatically
detects speed of link under test
- Economically
priced
- Fully
Lead Free and RoHS compliant
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- Bus-powered
for convenience of use
- Input
for optional external power (not required, but
useful if host won't configure a high-power
device)
- High
Speed USB (480 Mbit/s) connection to host PC
- Feature
connector provides signals for oscilloscope
or logic analyser
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Software
Overview
The Packet-Master
USB-12 owes a large part of its functionality to the
GraphicUSB application, which is supplied with the unit.
A simple, yet information-rich display allows you to
view every detail of a capture.
This shows
the organisation of the screen after a typical capture:
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Software
Features
- Capture
controlled from USB12 unit or from Application.
- Captured
document shows every detail of data transactions
graphically for a fuller understanding of the
USB protocol. This includes a detailed visual
analysis of each packet.
- Transactions
are grouped and summarised with a header row
in the event pane. Control transfers are summarised
with a special header row.
- Filters
allow less significant information to be removed
from the display to allow you to concentrate
on the critical data.
- Each
event is analysed in detail, with any significant
features explained, and possible errors or warnings
highlighted.
- Data
pane shows the data content of any packet.
- Comprehensive
search functions.
- Events
display, detail analysis or data can be printed.
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Standard software up-grades are free of charge
from our web site.
- Software
can be freely used as a viewer in the absence
of the Analyser Hardware.
- A
multi-document interface allows comparison between
captures.
- Capture
size only limited by RAM size.
- Optional
Class Analysis Modules.
Download
GraphicUSB and try it out
The
downloadable package
contains the full current release of GraphicUSB,
together with some sample captures for you to
examine. The sample files are in a folder:
C:\Program
Files\MQP Electronics\GraphicUSB\Samples
This
also demonstrates how you can view capture files
in the absence of a Packet-Master USB12 Analyser.
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Mixed Speed
on a Single Link
This
view of part of a screen shot from Graphic USB shows a
representation of data being transferred at two different
speeds on the same link. Each packet is preceded by a
coloured marker indicating Full Speed or Low Speed. This
makes the function of the PREAMBLE packet very clear.
Each event has a precise timestamp (left). Notice also
the detailed timing information for Hub Setup time, End
of Packet duration, and IDLE state time.
View
by Control Transfers
(less significant events filtered)
By
clicking on the filter buttons for less significant event
types, the sequence of top-level control transfer headers
may be viewed in isolation. This ability to view information
at an appropriate level of complexity makes Graphic USB
an invaluable tool for getting straight to the heart of
the matter.
Full
Analysis and Data Panes
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By clicking
on an event row in the event pane, a complete analysis
of the event is displayed in the analysis pane,
and the data content is shown in its entirety in
the data pane. Where relevant, any information selected
in the analysis pane is highlighted in the data
pane for easy identification. All standard requests
and descriptors are analysed in detail. Discrepencies
are described.
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Optional
Class Analysis Modules
A
number of Class Analysis Options are in preparation. The
following are now available:
- Human Interface
Devices (HID)
- Hub Class
- Communications
Class
- Printer
Class
- Mass Storage
Class
Registering an option allows Graphic USB to display Class
transfers in a more readable form.
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The screen
shot to the left shows the analysis of a HID Report
Descriptor.
The shot
below shows the results of the built-in 'HID Report
Descriptor' parser. Each report defined by the Report
Descriptor is identified and displayed.
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With
the HID Class Analysis enabled, each HID report
is identified, and the contents analysed.
Examining
the analysis of existing devices is an excellent
way to learn how a class works, and it has never
been easier to reveal the building blocks, than
with Graphic USB.
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Test
Set-up Connections
To
achieve a good capture rate it is important to provide
a suitable test environment. The Packet-Master USB12 should
preferably be hosted by a good performance PC with a high
speed USB connection. This USB host controller should
not be shared by any other USB device while doing the
testing.
The
Packet-Master USB12 will function correctly when connected
to a Full Speed link but the capacity wil be severely
reduced and only low rates of USB traffic may be captured
from the device under test.
In
a similar fashion it is theoretically possible to use
the same host computer for the Packet-Master USB12 and
for the Host Under Test. We do not recommended this, but
if it is absolutely unavoidable, then you must at least
use a separate USB host controller for the device under
test. If your computer does not have two host controllers
then you will need to buy a plug-in USB host controller
card.
Cables
As
this test equipment, by its very nature, has to connect
to a junction of two USB cables in order to probe the
data on the link, it is important to keep the cables between
the 'device under test' and the 'host under test' as short
as possible (for example 1m), and to use good quality
cables.
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Installation
Quick
and easy with self-installing software.
System
Requirements
(for
supporting Packet-Master USB12)
- Pentium
3 - 600MHz
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PC with High Speed USB port should be dedicated
to the capturing. (Actual target device should
be connected to a different Host Computer to ensure
reliable capture bandwidth)
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Windows XP (Service Pack 1 or better) preferred.
Also Windows 2000 / ME / 98SE.
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CD ROM / DVD Drive
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128MB RAM
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100MB space on Hard Disk
Note:
A good performance machine is recommended for good
capture rate.
Physical
Specifications
| Weight: |
155
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| Dimensions: |
129
x 100 x 31 mm |
| Temperature: |
0°C
- 40°C
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| Humidity: |
20%
- 80% non condensing |
Electrical
Requirements
The
Packet-Master USB12 normally derives its power from
the Host computer's USB connection.
| Power: |
150mA
from USB host
Optionally zero mA from USB if powered externally |
Safety
CE
compliant.
Signals
Available on Feature Connection
- D+
- D-
- Decoded
Data
- Decoded
Clock
- Packet
Sync Detected
Standard
Accessories
Packet-Master
USB12 comes complete with the following:
- Graphic
USB control software on CD
- USB
2.0 cable x 2
- Manual
on CD
Optional
Accessories
- Feature
Connector Terminating Board
- External
Power Supply
Software
Options
- Individual
Class Analysis Options
Availability
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