PassMark USB 2.0 Loopback Plug test coverage

[blusche]

PassMark Developer,

I have a several PC products now that have multiple USB ports on the motherboard, typically 2-6 separate ports.
- Will only 1 LoopBack plug be acceptable to test a cluster of USB ports
on a standard Intel/AMD motherboard ?
- Besides the actual connector itself which obviously will not get tested,
will there be any test coverage for the circuitry to the other USB ports.
(i.e. USB hub, controller, etc.)
- Is there a test coverage spec for the USB Loopback plug ?

Thanks, Bill

[Ian (PassMark)]

- Will only 1 LoopBack plug be acceptable to test a cluster of USB ports
on a standard Intel/AMD motherboard ?

Acceptable depends on the test goals. Generally, I would say that it is probably not enough to test a single port.

The USB 2.0 Loopback plug was designed to test the USB port and USB sub-system. We recommend using a USB 2.0 Loopback plug per port. If this cost is prohibitive, then you could potentially run a BurnInTest ( http://passmark.com/products/bit.htm ) scripted test to test one port at a time and manually move the plug after each test phase.

In saying this, testing one port will somewhat test the USB-subsystem, such as, the USB Host controller is functioning (at least for that port).

- Besides the actual connector itself which obviously will not get tested,
will there be any test coverage for the circuitry to the other USB ports.
(i.e. USB hub, controller, etc.)

Yes, the hub it is connected to and the USB Host controller. But a single port test will be less extensive, and as you say it won't test the connector for the other ports, or that the USB sub-system is working for the other ports.

- Is there a test coverage spec for the USB Loopback plug ?

The closest we have is the device specification on this page:
http://www.passmark.com/products/usb2loopback.htm