This is the mail archive of the ecos-discuss@sourceware.org mailing list for the eCos project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: SPI and 9 bit transfers (on AT91)


>>>>> "Peter" == Peter Niebert <peter@niebert.com> writes:

    Peter> Just to be sure, this means that the count would be
    Peter> "shorts" rather than "bytes" in the case of transfers
    Peter> between 9 and 16 bits? I will soon be able to post a
    Peter> patched version of the at91_spi driver that allows for
    Peter> different bit length transmits.

    Peter> Cheers and thanks for eCos, again and again.

The count is the number of data items to be transferred. If the count
is 100 and the SPI device is set up for 9-bit transfers, both tx_data
and rx_data should point at arrays of 100 shorts, i.e. 1600 bits. Only
900 bits would actually get transferred over the SPI bus.

Bart
    
-- 
Bart Veer                                   eCos Configuration Architect
eCosCentric Limited    The eCos experts      http://www.ecoscentric.com/
Barnwell House, Barnwell Drive, Cambridge, UK.      Tel: +44 1223 245571
Registered in England and Wales: Reg No 4422071.

-- 
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]