lpcware

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
Hi:
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,

Regards,
AC

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