On Apr 9, 2005 3:32 AM, Mark A. Greer <mgreer at mvista.com> wrote: > If you don't have an RTC, you shouldn't be using any todc_xxx routines.
Yeah, I figured this much :) > There are several platform files that explicitly set tb_ticks_per_jiffy > and tb_to_us. Did you try looking at those? Actually that didnt occur to me since I thought it was related to the supplied oscillator. Not knowing what their board is equiped with, I couldnt trust their value any more than my estimated value. But reading your next comment, it seems that it's related to processor as well. > Also, 33MHz does not sound right but then you don't say what processor > you're using so who knows. You need to find the bus freq used by the > cpu/system. Try looking for the freq of the processor's SYSCLK input. > Then you probably have to divide that by 4 to get the frequency that the > decrementer runs at. That's the value that you should use for the > 'freq' variable in the example code you included in your email. Okay guess I had all these things mixed up in head. What I should have said is, source to PCI_SYNC_IN is 33MHz. Anyway, following the MPC8245 hardware Spec pdf file, I was able to find the peripheral logic/memory bus clock to be 99,000,000. Dividing that by 4 like you said, gave me the value of 24,750,000. Which is I've used it to get very real 1 second :) BTW, why do you have to divide it by 4 ? -- Daniel
