[U-Boot-Users] main clock calculation invalid
Wolfgang Denk
wd at denx.de
Thu Apr 19 20:14:14 CEST 2007
In message <0721A2B6C14.000002EAejr at inbox.com> you wrote:
>
> > I'm sorry, but the user's manual for my Z80 processor does not contain
...
> I'm not sure what you're missing but my emphasis was on the calculation.
> This is on an ARM9 LH7A404 chip. Now I might be missing something but even
> on a 16 bit CPU
You did not understand my little joke about the old Z80 CPU - what I
wanted to pointout was that you completely left out all relevant
information, like which architecture and CPU and board you were
talking about.
> the calculation result shouldn't change, no?
You might have overflows here and there...
> and CONFIG_SYS_CLK_FREQ is 14745600.
It should probably be 14745600L or "UL".
> ulong maindiv1, maindiv2, prediv, ps;
^^^^^
> printf("maindiv2: %d, maindiv1 %d, prediv %d, ps %d\n",maindiv2,maindiv1,prediv,ps);
^^ ^^ ^^ ^^
%d is for int, not for ulong.
> printf("CONFIG_SYS_CLK_FREQ: %d \n",CONFIG_SYS_CLK_FREQ);
Same here.
> return ( ((maindiv2 + 2) * (maindiv1 + 2) * CONFIG_SYS_CLK_FREQ) /
> ((prediv + 2) * (1 << ps)));
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, HRB 165235 Munich, CEO: Wolfgang Denk
Office: Kirchenstr. 5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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