On Wednesday, November 04, 2015 at 04:45:20 PM, Aleksander Morgado wrote: > On Wed, Nov 4, 2015 at 4:33 PM, Marek Vasut <ma...@denx.de> wrote: > > On Wednesday, November 04, 2015 at 04:19:45 PM, Aleksander Morgado wrote: > >> On Wed, Nov 4, 2015 at 4:18 PM, Vostrikov Andrey > >> > >> <andrey.vostri...@cogentembedded.com> wrote: > >> >>> > About the parity -- can we add some flag into the datagram to > >> >>> > indicate we want hardware to calculate the parity for that > >> >>> > particular datagram for us? And we'd also need to indicate what > >> >>> > type of parity. I dunno if this is worth the hassle. > >> >>> > >> >>> This is HW configuration property, it does not belong to datagram. > >> >>> Also for TX channels, parity could be two kinds: odd and even, > >> >>> for RX it is only on/off. > >> >> > >> >> There are datagrams which do contain parity and ones which do not > >> >> contain it, correct ? Thus, it's a property of that particular > >> >> datagram. > >> > >> All ARINC words have bit #31 as parity bit; whether it's used or not > >> depends on the setup as Andrey says below. > > > > Can bit 31 be ever used for DATA instead of parity ? Or is this just me > > not understanding the parlance of the specification, where "DATA" > > actually means "DATA with parity" ? > > Well, as far as I know bit 31 is always parity bit, never used for > actual data contents. Which is the spec section that got you confused? > Maybe I'm the one which didn't read it well?
Sorry for being so late into the discussion. I got confused by hi-3585_v-rev-l.pdf page 7 right, CR4 lets you treat bit 32 as either data or parity. But I guess this is not the general case. So I wonder, does it make sense to treat the P bit as data always and do parity in software or not ? Best regards, Marek Vasut -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
