From: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Christophe Leroy <christophe.leroy-GgN8y9CXRhA@public.gmane.org>
Cc: linux-spi <linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: How to handle SPI components requiring heading/leading clock cycles with CS off
Date: Wed, 24 Aug 2016 12:27:02 +0100 [thread overview]
Message-ID: <20160824112701.GE22076@sirena.org.uk> (raw)
In-Reply-To: <9e854e9d-146c-61ea-da6e-a46b316b56c5-GgN8y9CXRhA@public.gmane.org>
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On Wed, Aug 24, 2016 at 01:19:50PM +0200, Christophe Leroy wrote:
> No I can't see any special reason for this. But I can confirm that without
> the two additional clock cycles with CS\ high, the commands are not taken
> into account.
Right, I just looked at the datasheet and it says in the serial control
interface section that it needs a three clock cycle idle state. Clearly
the designers weren't having a very good day when they did the digital
here but based on that you probably only need to send an extra byte with
chip select deasserted at the end of the transfer to satisfy it rather
than padding at both start and end. Like I say it'll need a new core
feature though.
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prev parent reply other threads:[~2016-08-24 11:27 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-23 16:10 How to handle SPI components requiring heading/leading clock cycles with CS off Christophe Leroy
[not found] ` <79679118-c092-1f9c-1972-0bb81bc59411-GgN8y9CXRhA@public.gmane.org>
2016-08-24 9:44 ` Mark Brown
[not found] ` <20160824094456.GB22076-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2016-08-24 10:49 ` Christophe Leroy
[not found] ` <8c6cbd99-7dd8-bbbf-89ee-a33752ab3063-GgN8y9CXRhA@public.gmane.org>
2016-08-24 10:56 ` Mark Brown
[not found] ` <20160824105640.GC22076-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2016-08-24 11:03 ` Christophe Leroy
[not found] ` <15444613-2f3d-9417-7d81-e545058afdf0-GgN8y9CXRhA@public.gmane.org>
2016-08-24 11:12 ` Mark Brown
[not found] ` <20160824111206.GD22076-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2016-08-24 11:19 ` Christophe Leroy
[not found] ` <9e854e9d-146c-61ea-da6e-a46b316b56c5-GgN8y9CXRhA@public.gmane.org>
2016-08-24 11:27 ` Mark Brown [this message]
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