Hi Adrian,
On 2016/3/3 21:37, Adrian Hunter wrote:
On 03/03/16 04:36, Shawn Lin wrote:
Controllers use data strobe line to latch data from devices
under hs400 mode, but not for cmd line. So from emmc 5.1, JEDEC
introduces enhanced strobe mode for latching cmd response from
emmc devices to host controllers. This new feature is optional.
As I currently understand it, HS400ES does not require tuning.
Consequently you can go straight to HS400ES and do not need to do
HS200 first. If that is the case then more changes are needed.
That's the case, and it's already in my plan before I going to remove
"RFC" prefix. From my experience of developing emmc-device firmware, the
only reason we need tuning for HS200 before we switch it into HS400
is that although data-line can be latched by DS but the cmd-line is
still in SDR mode when runing in HS400. With hs400-es setuped, tuning
and retune stuff is meaningless. ALl the SI should be guranteed by HW
design to regulate the PCB payload.
Also it would be nice if the transfer mode displayed reflected enhanced
strobe e.g.
Great idea! And maybe more thing should be done for core/debugfs.c
It seems to big change for init_card, so I need more time to split my
step for changing it to make the change will not do any side effect from
non-hs400es procedure. :)
Thanks.
Currently
mmc1: new HS400 MMC card at address 0001
Change for enhance strobe supported
mmc1: new HS400ES MMC card at address 0001
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