On 10/22/20 12:29 PM, yegorslists@xxxxxxxxxxxxxx wrote: > From: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx> > > Use table markup to show the PGN structure. > > Signed-off-by: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx> > --- > Documentation/networking/j1939.rst | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/Documentation/networking/j1939.rst b/Documentation/networking/j1939.rst > index faf2eb5c5052..f3fb9d880910 100644 > --- a/Documentation/networking/j1939.rst > +++ b/Documentation/networking/j1939.rst > @@ -71,10 +71,14 @@ PGN > > The PGN (Parameter Group Number) is a number to identify a packet. The PGN > is composed as follows: > -1 bit : Reserved Bit > -1 bit : Data Page > -8 bits : PF (PDU Format) > -8 bits : PS (PDU Specific) > + > + ============ ============== =============== ================= > + PGN > + ---------------------------------------------------------------- > + 25 24 23 ... 16 15 ... 8 ICan you add a row description that indicated that these numbers are. They are probably bit positions within the CAN-ID? > + ============ ============== =============== ================= > + R (Reserved) DP (Data Page) PF (PDU Format) PS (PDU Specific) > + ============ ============== =============== ================= > > In J1939-21 distinction is made between PDU1 format (where PF < 240) and PDU2 > format (where PF >= 240). Furthermore, when using the PDU2 format, the PS-field > Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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