Re: [Linuxptp-users] time stamping accuracy of Freescale P2020

[Mozhdeh K. <kam...@gm...>]

I think I found the answer:

There is no hardware timestamping in VSC7385 L2 switch. Time stamping in
P2020 has done in the MAC before the FIFO, so it's still in hardware.

So, is this accuracy enough? or maybe it is enough for testing?
-- 
*Mozhdeh *


On Mon, Apr 22, 2013 at 11:20 AM, Mozhdeh Kamel <kam...@gm...>wrote:

>
> Hi,
>
> I thought it is better to open a new discussion for this topic :)
>
> I am a bit getting confusion about accuracy of P2020 reference board. I
> could not find any timestamping accuracy in its datasheet. Ii seems it uses
>
> — 10/100/1000 BaseT Ethernet ports:
> – eTSEC1, RGMII: four 10/100/1000 ports using Vitesse™ VSC7385 L2 switch
> – eTSEC2, SGMII: one 10/100/1000 port using Vitesse™ VSC8221
> – eTSEC3, RGMII: one 10/100/1000 port Vitesse™ VSC8641
>
>
> I know VSC8221 and VSC8641, doesn't have hardware timestamping. But how
> about VSC7385 L2 switch? I could not find in its datasheet, but maybe I
> made a mistake!!
>
> If none of these ports doesn't have hardware timestamping, how P2020 can
> be accurate enough to even consider as a boundary clock?
>
> --
> *Mozhdeh *
>