[U-Boot-Users] get_timer versus get_ticks

Robert Deliën robert.delien at nxp.com
Fri Dec 8 13:23:39 CET 2006



I am currently straightening out lib-mips/time.c to make its granularity
defined by CFG_HZ (=1000) instead of the processor’s frequency at which MIPS
counters normally run.


Can somebody explain me what the difference between get_timer and get_ticks
is? Get_timer returns the current value of the timer in 1/CFG_HZ units, as I
would expect. I would expect get_ticks to return the raw counter value, but
that value would useless because there’s no way to tell what speed it’s
running at: get_tbclk is returning CFG_HZ and not the actual counter
incremental frequency. In common/main.c get_ticks is used in conjuction with
get_tbclk as if it were get_timer. This indicates either get_tbclk should be
returning the actual counter incremental frequency, or get_ticks to return
the same value as get_timer(0).


I have looked at the PPC implementation, but that wasn’t of much help
because there a hardware time base is used so that solution always correct.


Thanks in advance!


With kind regards,



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