Testing of USB hub

Details Testing of USB hub Testing of USB hub

1998-11-16

2002-05-21

Iqbal, Nadeem (Department: 2184)

Error detection/correction and fault detection/recovery

Data processing system error or fault handling

Reliability and availability

C710S105000

Reexamination Certificate

active

06393588

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to the testing of a USB hub.
BACKGROUND OF THE INVENTION
The Universal Serial Bus (USB) is a peripheral bus specification developed by PC and telecom industry leaders. Under the specification, the USB allows the plug-and-play capability of computer peripherals outside the PC case. The capability eliminates the need to install interface card into dedicated computer slots and reconfigure the system each time a peripheral is attached or detached from a PC. The USB specification is described in detail in the Universal Serial Bus Specification, Revision 1.0 published Jul. 15, 1996.
As shown in
FIG. 1
, the computer system
10
connects USB devices with a USB host
12
, i.e. a computer system. There are two types of USB devices: the hub
16
and the function
14
. A hub
16
is device which provides additional attachment points for the Computer system. A function
14
provides capabilities to the computer system. For instance, a keyboard, a mouse, an ISDN connection, a scanner, an audio device etc. Generally, there are two ports of attachment in the USB host
12
. The port
1
connects to hub
16
by the wire
18
. The port
2
connects to the function
14
by the wire
13
. HUB
16
connects to the functions
14
by the wires
15
respectively. Under the protocol of USB standard, the functions
14
are classified into mainly three types of device. The first one is the type of a human-interface device (HID), i.e. keyboard, mouse, or, alternately, an interrupt device. The second one is the type of a bulk device, i.e. a scanner, which places strict requirement on accuracy of each data bits transmitted. The third one is the type of an isochrome device, i.e. an audio device, which does not place strict requirement on accuracy of each data bits transmitted. The detailed definitions of these types of device may be referred to in the Specification mentioned above.
Hub
16
are therefore a key element in the plug-and-play architecture of computer system
10
, and is wiring concentrator which enable the multiple attachment characteristics of USB. The upstream port of a hub
16
connects the hub
16
towards the host
12
. Each of the downstream ports of a hub
16
allows connection to another hub or function
14
. Hubs
16
detect the attachment and detachment of a USB device
14
at each downstream port and enable the distribution of power to these down stream USB devices
14
. The wires
13
,
15
and
18
all named as USB lines.
The present invention relates to the testing of a USB hub
16
. With one conventional approach regarding the testing of a USB hub
16
, all testing commands and return status are transmitted through the USB lines
15
and the hub
16
between the host
12
and the USB devices
14
. However, since the hub
16
is a target to be tested, and as the USB command is issued to the downstream devices
14
via the USB line
15
and hub
16
, the locations of errors can not be accurately determined as errors are encountered. Furthermore, some conventional testing methods are performed under the DOS environment which are substantially different from actual WINDOWS 98 environment.
SUMMARY OF INVENTION
Therefore, it is the main object of the invention to provide an apparatus which emulates a downstream USB device to a USB hub to test whether the USB hub being tested operate normally.
A test apparatus for testing function of a USB hub under the control of a USB host computer is provided. The USB host computer issues a USB command during the test. The test apparatus includes a USB bus, an emulation device, a standard bus and a micro-controller device.
The USB bus is coupled to the USB hub. The emulation device emulates an USB device connected to the USB bus.
The standard bus is connected to the USB host computer. The microcontroller device is connected to the standard bus and the emulation device respectively to process a USB transaction corresponding to the USB command.
The invention provides a testing environment which is fully compliant to the WINDOWS 98 environment.
The advantage and spirit of the invention may be understood by the following recitations together with the appended drawings.


REFERENCES:
patent: 5859993 (1999-01-01), Snyder
patent: 5954827 (1999-09-01), Frank et al.
patent: 5974486 (1999-10-01), Siddappa
patent: 5978947 (1999-11-01), Kim et al.
patent: 5991897 (1999-11-01), Perugini et al.
patent: 6012115 (2000-01-01), Chambers et al.
patent: 6148354 (2000-11-01), Ban et al.
patent: 6175530 (2001-01-01), Theron et al.

Affiliated with

Also associated with

Rating

Testing of USB hub does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Testing of USB hub, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Testing of USB hub will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2870304