Jeremy Fitzhardinge wrote:
>
> On 21-Jan-00 H. Peter Anvin wrote:
> > There are no "x86 cycles" on Crusoe, so it counts VLIW cycles. In
> > fact, on TM5400 it counts *nominal* cycles, since the actual cycle
> > length is variable (due to LongRun).
>
> So RDTSC is useless for getting consistent udelay delays.
>
No, on the contrary. For a 700 MHz TM5400 the TSC will always count at
700 MHz even if the CPU decides that it currently only needs to run at,
say, 175 MHz.
-hpa
-- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot."- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun Jan 23 2000 - 21:00:27 EST