Date: Sat, 15 Jul 2006 12:34:29 +0930 From: "Daniel O'Connor" <doconnor@gsoft.com.au> To: cvs-all@freebsd.org Cc: cvs-src@freebsd.org, scottl@samsco.org, src-committers@freebsd.org, "M. Warner Losh" <imp@bsdimp.com> Subject: Re: cvs commit: src/sys/arm/at91 at91_spi.c at91_spiio.h at91_spireg.h Message-ID: <200607151234.38952.doconnor@gsoft.com.au> In-Reply-To: <20060714.155355.255408591.imp@bsdimp.com> References: <200607142135.k6ELZxol050056@repoman.freebsd.org> <44B81042.2090009@samsco.org> <20060714.155355.255408591.imp@bsdimp.com>
next in thread | previous in thread | raw e-mail | index | archive | help
--nextPart1490657.aQAetEoLkj Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Saturday 15 July 2006 07:23, M. Warner Losh wrote: > SPI =3D=3D Serial Peripheral Interface. It is common in the embedded > world. The 'bus' is nothing more than 4 signals: chip select, clock, > MOSI (master out, slave in) and MISO (master in, slave out). Lots of It's not even a bus, only a point to point interface. > cool things live on the spi bus, but I'll just be committing support > for AT45 DataFlash parts. The framework is general enough to support > other things. In one of the hardware hacking lists I'm on, people > were talking about writing a driver for a SPI Ethernet whatsit, but > I'm unsure how that works, since there's no interrupt signal on this > bus... You can poll it (the Microchip ENC28J60 anyway) or assign a GPIO pin as an= =20 interrupt line. There is a TCP stack for the various 16 bit micro that can use it. http://www.sics.se/~adam/uip/ Another interesting SPI part is the Maxim MAX3420E - it is a USB slave=20 interface. http://www.maxim-ic.com/quick_view2.cfm/qv_pk/4751 (As you might have guessed I am looking at using these parts, although with= a=20 16 bit AVR, not this fancy ARM stuff :) Another way to use the SPI would be to connect a microcontroller and slave = it=20 to the ARM for whatever thing you might need that isn't already built into= =20 it.. =2D-=20 Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C --nextPart1490657.aQAetEoLkj Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (FreeBSD) iD8DBQBEuFtG5ZPcIHs/zowRAlKEAJwMftzi2utV5em0NNXSeAPOdbLpgACfXQvo idAgC6l8jkxmIDl0U4RYAbE= =pWYw -----END PGP SIGNATURE----- --nextPart1490657.aQAetEoLkj--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200607151234.38952.doconnor>