I am currently attempting to run some speed tests provided by Datalight (vendors of the Reliance Edge File System). I have therefore integrated FreeRTOS, Reliance Edge and ASF SD card drivers together onto a SAMV71 Xplained board.
The result is that I have a Reliance Edge File system running from an SD card. This has been all good... But I have found that the ASF SD/MMC driver code only appears to function correctly if all the data is written to the card using a multi-block-transfer (SD card CMD25). I find that a single block transfer (CMD24) seems to result in a response timeout (MAXLAT exceeded). I have not chased this down further and am living with multi-block transfers only.
Is there a reason that CMD24 might not work and CMD25 work just fine?