need help w/ Cora-Z7, XC7Z007S Zynq board
Thomas Skibo
thomas-bsd at skibo.net
Sun May 17 19:14:23 UTC 2020
On Sat, May 16, 2020 at 11:38:53PM -0700, John-Mark Gurney wrote:
>
> After a bit of digging, I think I have found the solution. It looks
> like slcr is suppose to be set to the frequency of the ps clk, which
> is 50 MHz, and then the global_timer is suppose to be set to half the
> CPU clock frequency, which on this board is, I believe, 650 MHz, so
> using the following in the dts made things work:
> &slcr {
> clock-frequency = <50000000>;
> };
>
> &global_timer {
> clock-frequency = <325000000>;
> };
>
> ping times look good sane (after I realized that wifi has a tad slower),
> and I've been running ntpd for over 20 minutes, and it hasn't bombed
> out yet, and the offset/jitter look good.
>
> --
> John-Mark Gurney Voice: +1 415 225 5579
>
> "All that I will do, has been done, All that I have, has not."
> _______________________________________________
> freebsd-arm at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-arm
> To unsubscribe, send any mail to "freebsd-arm-unsubscribe at freebsd.org"
>
sysctl hw.zynq will tell you the ARM PLL frequency. It is probably set
to 1300 Mhz so 325 Mhz is the correct global timer frequency.
--Thomas
--
=====
Thomas Skibo
thomas-bsd at skibo.net
More information about the freebsd-arm
mailing list