USB Certification

[PHXFAE]

I have a customer designing with the MK20Dn512VLK10.  He is asking about USB certification and the process he will have to go through for that.  I found this web site:  Universal Serial Bus (USB)|Freescale 

There is a nice video describing some of this.  There is also a chart indicating which Freescale products are USB certified devices.  Can someone tell me what it means that these are Freescale Certified devices?  Can the customer used Freescale's certification or is this only an assurance that these parts will pass the testing?  Is there any documentation from Freescale about this process?  Is there any other help or info you can offer?  Thanks.

[Hui_Ma]

Hi Alex,

I agree with Mark's comments.

The USB.org certifies USB products.

There are several types and levels of certifications, from physical layer certification to full class certifications. Depending on the type of device USB.org has definitions of what types of tests the application has to go through to be able to expose the USB logo in the product.

The Freescale USB-Certified Devices provide related USB hardware design and related USB software stack to help customer to pass the USB related certification test.

Wish it helps.

Have a great day,
Ma Hui

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[mjbcswitzerland]

Hello Alex

You can get full details of USB-IF certification at USB.org - USB-IF Compliance Program

Basically, compliance is optional - products can be produced and sold without compliance testing but they cannot use the USB (compliance) logo.

The logo is in some ways a marketing aid since it shows buyers that the product passed the compliance testing, which (sort of) guarantees that it will have a good compatibilty with other devices.

The compliance testing is not cheap and one can expect maybe $10k of costs for the process - I am not sure, but possibly $4k a year recurring costs for USB membership. The reasons that I am not sure is that, although I have developed a number of USB products together with various companies (mostly fairly small companies but also some big international companies too), I think that all have decided against using the logo.

I believe that Freescale has completed such testing since it proves that the hardware (and the used SW in the tests) "can" be successfully certified - to give semiconductor users confidence. Once different products, with different SW, are made with the same HW base the tests need to be repeated since it is a new case.

Testing gives a high level of confidence that the product is also good but doesn't mean that it is perfect. There are various bugs in the stack used for the complience testing as seen by a number of threads discussing them - for example, see the list of many dangerous or serious issues discussed by johnstrohm

My experience is that companies who make good products prefer to do their own serious testing of their product's suitability in its intended environment and convince "themselves" of its performance and reliability, rather than go for certification and maybe miss issues that are important to them. Of course both would be best if the resources (man-power and financal) are available but this is often not the case.

Companies like Logitech would of course always certify since they make consumer products in high quantity and there is no option, but industrial/niche products may not see any real benefits - they must work realiably but a logo on the box is not always a big deal to this aim.

A bigger issue seems to be certified drivers for use together with the products - no user likes drivers that are not certified, even if it just means clicking a box once on first use - but thankfully certificates can be purchased quite cheaply (around $100) and so this can be solved quite easily and cheaply in comparison.

Regards

Mark

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