Le Tuesday 28 April 2009 14:20:11 Thierry Reding, vous avez écrit : > * David Brownell wrote: > > On Tuesday 28 April 2009, Thierry Reding wrote: > > > This second version is pretty much a rewrite. > > > > That happens sometimes... > > > > > Some notes about the most > > > important changes: > > > > > > * uses per-chip states to allow more slaves to use the controller > > > concurrently > > > * rejects invalid device configurations during setup > > > * rejects invalid per-message and per-transfer options > > > * queues messages so that they can be processed one after another > > > - this also provides for a way to handle power-management > > > * omits the spioc.h (and with it the platform data structure): > > > - uses the platform_device.id for the bus number > > > - always uses 8 chipselects because that's the maximum that the > > > core supports > > > > All that sounds good. > > > > > I couldn't really find a way to implement per-transfer overrides for > > > the word size because the controller simply has no concept of word > > > sizes. Is it in such cases still necessary to hardwire the word size to > > > 8 bits? > > > > Is this the http://www.opencores.org/?do=project&who=spi core? > > Yes, it is. > > > Its summary says "Variable length of transfer word up to 32 bits"; > > does that mean "configurable when core is synthesized" instead of > > truly "variable"?
This is indeed configured at synthesis time. > > That summary seems out-dated. The variable length of transfer word is > actually the maximum length of a single transfer and is 128 bits in the > latest version. So you get 4 registers, each 32 bits wide into which you > program the data you want to transfer. Then you set the number of bits of > that transfer so the core knows which registers and what bits of those > registers to shift out serially. -- Best regards, Florian Fainelli Email : flor...@openwrt.org http://openwrt.org ------------------------------- ------------------------------------------------------------------------------ Register Now & Save for Velocity, the Web Performance & Operations Conference from O'Reilly Media. Velocity features a full day of expert-led, hands-on workshops and two days of sessions from industry leaders in dedicated Performance & Operations tracks. Use code vel09scf and Save an extra 15% before 5/3. http://p.sf.net/sfu/velocityconf _______________________________________________ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
