Can older microprocessors (such as LPC2292/LPC2294) work with USB 3.0 CPUs/chipsets?

[jason_atm]

I have a serial device that is not recognized when attached to a serial port on my desktop docking station.  The dock connects to the laptop via a USB 3.0 host controller, so the serial port on the dock is USB3-to-serial utilizing an FTDI driver.  The laptop itself has an Intel Skylake architecture, so all USB devices are USB 3.0 only.  The laptop itself has a true serial port which works without issue, but the docking station is needed for other applications, and the serial port on the system is not accessible when the unit is docked?  I understand that the are legacy devices and no longer supported, but looking for confirmation that they will not work at USB 3.0 speeds or any workarounds if available. Thank you.

[CarlosCasillas]

Hi John,

By spec, all USB 3.0 controllers must be completely backward compatible with all USB 2.0 devices. However, this compatibility is also dependent of the chipset and from the related driver on the host operating system, being it cause of some compatibility issues with USB 2.0 devices.

From the Device point of view, the USB communication should be transparent, but the issues are often related to the host operating system drivers, in the most, by the transition from 32-bit OSs to 64-bit OSs (independently of being USB 2.0 or USB 3.0 controllers), missing its driver or having compatibility issues with legacy Devices.

Hope this will be useful for you.
Best regards!
/Carlos
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[jason_atm]

Thank you for the information.  Further testing has shown that, while the Philips LPC2000 Flash Utility will not work, Flash Magic does work using the exact same settings. This is encouraging, but looking for some clarification if possible about what would cause the incompatibility with the Philips application.  I do know that the LPC2000 app is considered out of date, legacy, archaic (all adjectives I have read online) and Flash Magic is the recommended application to use  now. For this organization, the Philips utility has always been used in the past, and it will take some effort to re-train many users in a large organization on a new tool.  As noted above, the Philips utility has always worked and continues to work with true RS232 ports.  It will not, however, work with the FTDI USB-to-serial device on the docking station (which passes through a USB 3.0 hub on the laptop).  Still wondering if the USB 3.0 piece is the issue.  I know USB 3.0 was brand new and not widely available when the last version (2.2.3) of the Philips tool was released.  Curious if others have seen the same thing or if this is a known problem.  It is difficult to find a lot of documentation for the Philips utility since it is so old and many of the original support documents are no longer online.  Any additional information would be appreciated.

We have tried every available baud rate, buffer settings, latency settings, etc., all with the same result; "Cannot communicate with test board."

[bernhardfink]

I don't think that the legacy device is the issue here. A serial port more or less must work, when you use hardware handshake. If you use RX/TX only, then these USB-2-Serial converters send to much data in one shot, which generates overflows on the LPC side.

Normally you have FIFO settings for these virtual COM ports, try to play with the parameters.

Regards,

Bernhard.