For the past 6 months I've been debugging an LPC1778 based target using a Keil ULink 2, running uVision 4.0 under Windows 7. Recently I had the need to do performance profiling, and I've tried to upgrade to a ULink Professional. I switched out the debugger device. Under uVision I switched both the flash and the debug debuggers from ULink 2 to ULink Pro. However, when I try to flash my target, or I tried to initiate a debug session I get the blue light that I expect, but then I get "USB Communication Failure." I'm running uVision 4.72, from which I manually installed the driver for the Pro (under the ARM folder.)
Is it likely there is something physically wrong with my debugger? Is there a USB setting which needs to be reconfigured?
Regards, Eric T.
Had a similar experience, replicated on multiple machines, in the end I replaced the USB cable with a higher quality shielded USB 2.0 480 MBps rated cable instead of the random one I'd picked off the bench.
Be advised that you should never remove the internal battery.
Thank-you for the feedback. I switched out the cable, and it's working now. You guys are the best
Glad that helped, I know it made me quite agitated.
I don't have the specs/part# for the cable I ended up with, but it was of a significantly more industrial construction (probably 24AWG or better), 6ft, clear with braided shielding.
Not sure of the exact design difference, but this world is full of USB 1.1 cables originating from the 12Mbit/s time.
So way slower than the 480Mbit/s of the newer transfer speed of USB 2.