Clock Modification of MPC885 for USB Host Functionality

[Prakash Ramaraju]

Greetings

Currently I have a MPC885 based board running at 50MHz. I want USB
host working at full speed with internal clock. Assuming I need to
change the General System Clock Frequency (GCLK2) to 48MHz, I got this
calculation with input frequency of 10MHz from an u-boot script.

pdf mfi mfn mfd s dbrmo     dpref    dpgdck     jdbck     gclk2 exact?
--- --- --- --- - -----     -----    ------     -----     ----- ------
  0   9   3   4 1     0  10000000 192000000  96000000  48000000    YES
  0   9   6   9 1     0  10000000 192000000  96000000  48000000    YES
  0   9   9  14 1     0  10000000 192000000  96000000  48000000    YES
  0   9  12  19 1     0  10000000 192000000  96000000  48000000    YES

I modified CFG_PLPRCR (to 19194000) in u-boot config file to match
this. But I'm getting only 45MHz output clock (not exactly 48MHz which
is needed for USB to work)

If anyone can shed some info making the USB work on MPC885 with
internal clock or changing the clock freq to exact 48MHz, it will be
helpful.


-- 
With best regards,
Prakash