Djoen,

The LogicLoader doesn't support the notion of a USB device. To my knowledge, neither does dBUG. Therefore, what you are seeing is what I would expect you to see.

You will have to write some software to make the device work how you want it to. If you are targeting a specific operating system (such as Linux, ARC, VxWorks, etc.) then most of the USB software will already be written. You will need to provide a driver though.

If you are not using an operating system, then you will have to write your code from scratch. Luckily, USB device software is *much* easier to write than USB host software.

What are you hoping to have the device do once it is connected to a host?

--mikee

I've received an e-mail from freescale that the usb device dousn't work on the M5475.

Thanks for response

JeroenC

Djoen,

That is the case. I forgot about the silicon issue. However, my original response still stands. No matter what happens when Motorola fixes the silicon, you will still have to provide some software which makes the device work. There are no default descriptors or anything. You have to get that all sorted out yourself.

Logic can help you do this if you like. We have plenty of experience with USB and developing USB drivers for various platforms.

You should also check out http://www.usb.org for information about the specific class of device you are creating.

Regards,
--mikee

We are thinking about using the 9s12UF32 kit for developing an usb Device. The reason for the development is to investigate the real-time characteristics of the usb2.0 protocol. A sensor detects an event. The host has to receive and process this event under 5ms.

Is the 9s12UF32 a good choice for developing an USB2.0 Device ?

Djoen,

I'm not recognizing the number "9s12UF32" off hand. Are you referring to one of our Motorola kits?

As far as investigating the real-time characteristics, you have a number of things to consider.

# USB-protocol itself:

* USB has certain transfer speeds and bus-bandwidth allocation schemes.
* You need to consider the amount of data being transferred with the device.
* You need to decide what type of USB-transfer mechanism you will use namely:

- Isochronous
- Bulk
- Interrupt
- Control


* You should probably take a look at http://www.usb.org/developers/usbfaq/#band1


# The host software environment:

* Interrupt Service Routine(ISR) latency
* Interrupt Service Thread (IST - if any) latency
* System Schedular
* Thread Priority of your test software in relationship to all other threads running on the system (if any).

All of those items will factor into the "real-timeness" of the end system. Fortunately, most of that can be calculated without ever writing any software. All of the USB bandwidth items are well documented. As far as your end system, the operating or other system software you choose to run should have information available as to the various latencies.

--mikee