Casainho wrote:
Hello :-)
We are working on Lyre project, a Free/Open hardware audio player
(DAP) and recorder, for use with RockBox firmware.
We want to boot our ARM9 from SD Card, but we would like to avoid the
need to pay royalties for using the SD BUS for communicate with card.
Does anyone knows if this ids true?
I think the royalties for the SD Bus are payed by the IC
manufacturer.
Or the manufacturer should pay the royalties? in this case, us, before
selling the hardware? - we pretend to assembly and sell on Ebay...
IIRC the licensing kicks in at the point a manufacturer
uses the SD logo to advertise their device as SD compliant.
But IANAL and things may have changed since I last looked at
this so you'll need to do some legwork to verify your legal
obligations relative to your situation. Start here:
http://www.sdcard.org/developers/howto
If you are adding an SD host controller to your device (or
paying for the same integrated into the SoC) it seems odd
not to use the controller -- if for nothing else than to
offload the CPU.
That said you could get by without a controller at audio
bit rates by talking to an SD card in SPI mode. This is
bit serial and only yields 25% of the theoretical maximum
bandwidth available in 4-bit SD mode. But it is cheap
and more than sufficient to transfer audio data to/from
the card. If you don't have a SPI controller you could
even bit bang an interface assuming you have sufficient
CPU bandwidth available.
--
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