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* confusion regarding the CMD19 and CMD21 in eMMC/SD card spec
@ 2011-09-15 11:58 ` Girish K S
  0 siblings, 0 replies; 14+ messages in thread
From: Girish K S @ 2011-09-15 11:58 UTC (permalink / raw)
  To: linux-mmc, linux-samsung-soc, linux-arm-kernel

Dear all,
             The eMMC 4.5 specification mentions that the CMD21 in
class 2 is a SEND_TUNING BLOCK command. where as the SD card
specification
in the given link says CMD19 in class 2 is the SEND_TUNING_BLOCK
http://www.scribd.com/doc/50685191/53/Figure-4-8-Send-Tuning-Block-Command.
Also the implementation in the drivers/mmc/host/sdhci.c uses the CMD19
as the SEND_TUNING_BLOCK.
Can anybody clarify why there is overlapping in this command number.
May be my understand is wrong.

In the MMC spec the CMD19 is BUS_TEST_W in class 0 and CMD21 is
reserved till eMMC 4.41 version.
But in the SD specification (given link) CMD19 is SEND_TUNING_BLOCK
and CMD21 is reserved.

Thanks and regards
Girish K S

^ permalink raw reply	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2011-09-16  6:14 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-09-15 11:58 confusion regarding the CMD19 and CMD21 in eMMC/SD card spec Girish K S
2011-09-15 11:58 ` Girish K S
2011-09-15 16:23 ` Philip Rakity
2011-09-15 16:23   ` Philip Rakity
2011-09-16  4:11   ` Girish K S
2011-09-16  4:11     ` Girish K S
2011-09-16  4:47     ` Aaron Lu
2011-09-16  4:47       ` Aaron Lu
2011-09-16  5:30       ` Girish K S
2011-09-16  5:30         ` Girish K S
2011-09-16  5:57         ` Aaron Lu
2011-09-16  5:57           ` Aaron Lu
2011-09-16  6:14           ` Girish K S
2011-09-16  6:14             ` Girish K S

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