AnsweredAssumed Answered

Does the PLL_STABLE bit in the USB_PLLOSC_CTRL work?

Question asked by mybandjoe on Sep 8, 2011
Latest reply on Sep 11, 2011 by JoeT



I am using the USB on the bf547M blackfin for attaching a HID device.  I have a 24 MHz oscillator hooked up to USB_XI pin.

I have several keyboards that work, but I have one keyboard that does not and I keep getting a frame timing jitter error.


When messing with the clocking I noticed that the PLL_STABLE bit in the USB_PLLOSC_CTRL register never gets

set to 1.  Does this bit work? I know this could mean that the PLL cannot lock to my 24MHz input clock.


I have another board setup here that has a 19.2MHz input clock from a very accurate oscillator.

This board does the same thing, the PLL_STABLE bit never gets set and all the same

keyboards work or don't work.


Thanks for your time,