There is a fault with the USB drive detection in the following situation.
The design contains iMx6 which has an internal USB hub that communicates with the external USB hub (Cypress CY7C65631-56LTXCT). The latter external hub switches itself off without reporting any faults to the processor when the USB drive is plugged after the system booted. This fault is reproducible and only occurs when no device has been plugged into the port during system power on. This has been occurring on current and previous boards involving the same Cypress hub.
This fault has not occurred when the Cypress CY7C65631-56LTXCT was bypassed and USB lines were connected straight into the processor.
Is there anything specific that the processor needs to tell the hub that could prevent the hub from powering off? All logs report no errors so is there any way we could configure the hub to echo something back before the fault occurs?
Thanks for posting in the Infineon developer community!
I would like to understand the problem better. Please answer the following :
- What do you mean by the fault here? Please explain more on this.
- Is the fault happening when the USB drive is connected to the hub?
- Do you have any issues with the USB drive connected?
- What do you mean by hub powering off? Whether the downstream port power switch turned off or the Hub enumeration itself is lost?
- Do you have a custom board with CY7C65631-56LTXCT silicon? If so, did you follow our HX2VL Hardware guidelines?
- Can you share the USB analyzer logs when the fault occurs both on the Downstream(where the USB drive is connected) and Upstream side?
- The fault itself is the unexpected shutdown/power down of the Cypress hub. The hub switches off without reporting back anything to iMx6.
- The fault happens approx. 1 second after any USB device is plugged into the USB port.
- No issues with the USB drive and I have used two different USB drives to test.
- The hub is physically switches off.
- Yes, this is a custom design. We followed the datasheet recommendations.
- USB analyzer log for the Downstream side is below. I will try and get the upstream log since I only have scope capture (see snapshots below).
Thanks for sharing the details.
Can you share the schematics of your design if not confidential? Is it a Bus-powered design?
Can you also share the USB Hardware analyzer(for Example Lecroy, Ellysis, etc.) logs to check USB messages between the hub and the device, Hub and the Host(For this you can also use the Wireshark software analyzer for now)? It will be difficult to check if you share the Scope capture.
Thanks for your prompt responses.
Unfortunately, the design files are confidential. It is indeed a bus-powered configuration.
The USB Analyzer is Totalphase Beagle 5000 USB Analyzer. I have shared the log for the downstream device as a snapshot in my previous reply - see Excel sheet snap. I will try to retrieve upstream port log - unfortunately it isn't as easy.