[U-Boot-Users] CFG_HZ value

[Wolfgang Denk]

In message <87A697E50899F541B77272C331CEB744D506 at exchange.Q-DOMAIN> you wrote:
> 
> Ok, so just to clarify:
> 
> If I run the following code on a 1GHz machine vs. a 300 MHz machine and
> assuming that the read_reg always equals 0:
> 
> tmo = get_timer (0) + 1 * CFG_HZ;
> while ((((read_reg(0xa6)) == 0)&& tmo < get_timer (0))
>                 /*NOP*/;
> 
> 
> then the timeout should occur much quicker on the 1 GHz machine as
> opposed to the 300 MHz machine.  The reason being that the timer will
> decrement much faster on the gig machine (assuming the timer is fed the
> system clock same as CPU).

No, this is not correct. The timeout  will  always  oocur  after  one
second.  get_timer() returns the time (minus the offset passed in the
argument) in milliseconds.

> Is this a correct analysis or am I missing something?  If true, then the

Yes, you are missing that get_time() is counting in milliseconds.

> timeout has to account for the clock of the timer (rate of timer

No, it has not.


Best regards,

Wolfgang Denk

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