(Adding linux CCs)
On 02/01/2010, at 7:19 PM, Hein_Tibosch wrote:
> Almost good: on my Kingston Elite Pro (50x) SD-card, initialization will
> only succeed if F <= 282258 Hz.
...
>
> I checked some datasheets of several makes:
>
> Delkin microSD min 0 max 400
> Swissbit min 0 max 400
> Sandisk 100 - 400
> Toshiba 100 - 400
> ST electronics 0 400
> SD-specification: Issue continues clock in frequency range of 100KHz-400KHz
> If the Average frequency of the SDCLK is less than 100KHz then the card
> may not be able to respond within the 1-second limit
>
> So what about 100 or 150 Khz?
Ah geez, yeah this something else I was hoping to avoid with the V1 patch - an
endless stream of "oh shit, this card's even /moore/ broken! Patch it, patch
it good"
Pierre, thoughts? All my cards were borderline spec but Hein's got a
mainstream, common card which seems to completely ignore the spec. Can we just
take the few-hundred-uS hit and allow initialization down at the bottom end,
say 100kHz?
<overkill> Or a KConfig option? </overkill>
--Ben.
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