LPC43xx UAB0 stops working after changing core clock frequency

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by casad on Sun Jan 20 10:15:54 MST 2013
I am using USB0 on LPC4350 platform. I am running a simple mass storage application using USB Host. USB0PLL is at 480 MHz and BASE_M4_CLK (PLL1) in running at any clock up to 204MHz. In my case core clock in 180MHz nad USB in working fine. But when I dynamically change the core clock  frequency from 180mhz to lets say 144Mhz, it stops working means after that I a unable to perform I/O operations on USB device. I have also tries switching to 172 Mhz its never worked either. At start-up I can set any frequency and its works but after that when i dynamically switch the frequency device become inaccessible.

The core clock BASE_M4_CLK (PLL) which i am changing is in the register interface clock. It should not have any effect on the device USB device which is running on PLL0USB 480 MHz.

Looking forward to you response,