I'm still trying to nail down the issues of not being able to get a M52223EVB to enumerate with a Windows 7 PC and one of the areas that has been identified to me is the use of the MAX3353 on the PCB. Just to recap, the USB driver (running CDC) runs fine under MQX 3.6.0 on the M52223EVB for Win/XP (and LInux) but has a problem with Win 7. I'm trying to figure out why it doesn't work under Win 7.
When I look at the MQX USB source code, I can't find any reference to the MAX3353 and when I read through the documentation, it looks like the part comes up in "shutdown mode" (which may affect the operation of the USB port, but I suspect that in shutdown, the MAX3353 is dormant except for the ESD protection diodes). Can anybody comment?
I decided to look through the various schematics for different PCBs that Axiom have created and discovered that there is a certain amount of differences, between the different Axiom PCBs which have USB on them:
CMM52229 - it looks like it is wired to act like a host (passing +5V to VBUS)
M522210DEMO - it can act as a Host or have the entire unit powered by USB
M52211EVB - has the same circuit as the M52223EVB
M52221DEMO - can be a Host or a device powered separately
M52259DEMOKIT - Looks like it can only be used as a device and can either be powered by the USB or a separate power supply
TWR-MCF5225X - I just thought I would look there as well. It has a very basic USB connection.
Within the various PCBs, there is a certain amount of changes for which lines are used for passing the USB_ID back to the Processor and which ones set the USB speed. I'm wondering if there could be a problem there.
Has anybody had any luck with any of these PCBs and Windows 7 with the MQX 3.6.0 (or later) USB drivers?
There is some urgency to this as I am starting to design our product PCB and I want to minimize spins due to USB issues.