[U-Boot-Users] PXA270 support

Wolfgang Denk wd at denx.de
Mon Mar 14 23:55:34 CET 2005

In message <71555548814716479478431542AA5F8A01B1B6D7 at dlee2k04.ent.ti.com> you wrote:
> > CFG_HZ should be 1000 on all boards. it has NOTHING to  do  with  any
> > clock  frequencies of your baord or processor (yes, I know that quite
> > a lot of boards are broken this way).
> Why is this?  The common use seems to be many flash drivers may get a
> time source directly and need to normalize the number of ticks to a

Mind the term "ticks" here. This is the "system tick", but not any of
the clocks applied to any of the CPU pins.

> second's value.  I know I set up my timer with the CFG_HZ value in mind
> to gauge udelays.

CFG_HZ is the number of "clock ticks" per second; it has exactly  the
same meaning as the HZ variable in the Linux kernel.

Like in current Linux kernels, U-Boot  normally  uses  a  1  millisec
system tick, thus CFG_HZ should be 1000.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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