I'm getting a report from the analyser software of a SPLIT transaction, and that it doesn't support these.

My first question, is why would this be the case when the device under test is not a hub, and is not trying to emulate a hub? From my reading of the USB2 specification SPLIT transactions are only for use with hubs when there is the possibility of a full/low speed device on the other side of the hub. The device being tested is an ARM SoC with a On-the-Go controller trying to emulate an RNDIS ethernet device.

My second question is that the software says the "professional" version should be able to cope with SPLIT transactions, but I cannot find any mention of this 'paid-for' version.

Would it be possible to skip the split transaction and keep on following the data?

Please send the temp.usb file generated in the installation directory to support(at)InternationalTestInstruments.com and we will analyze your capture file. We will look at adding an application option that simply ignores the SPLIT transactions so you can continue analyzing the rest of the capture. This should be a quick fix (a day or so).

The 1480A Analyzer must be directly connected between the device under test and an upstream hub. If you are using a downstream hub or possibly if you are using a hub on *another*port on the same host controller you'll see SPLIT packets on the link under test. This is because the host controller will broadcast all packets on ALL ports regardless where the target device is connected. Perhaps you are using a USB keyboard or another device that contains a hub on another port on the same host controller your device under test is connected to? The simplest workaround is to use a separate host controller for the link under test.

We are working on releasing a software version that handles SPLIT transactions. As of this time we don't have a release date.

Thanks, however lost the trace from that session. Have moved to a different host until a second EHCI card can be placed in the machine.

Turned out there was a full-speed USB serial chip on the same bus generating traffic from the debug port of the device being tested.

Good you found a workaround. We have decided to add SPLIT transaction support to the next software release (2.0) since it turned out not to be too complex to implement after all. The feature is soon implemented but we need some time for testing (new protocol parsing code is quite complex to validate). Keep an eye on the software update page the next few days.

Version 2.0 has now been released and can be downloaded from our download page. This version decodes SPLIT Transactions.