clk
cmd
(Left Border Case)
E
cmd
(Right Border Case)
S
ACMD12
1
2
3
4
5
6
7
E
S
ACMD12
E
Last Data Block
S
Next Data Block
dat
Functional Description
18.3.10.2 Auto Command 12 Timings During Read Transfer
With UHS very high speed cards gap timing between 2 successive cards has been extended to 4 cycles
instead of 2. By the way it gives more flexibility for Host Auto CMD12 arrival in order to receive the last
complete and reliable block. SD controller only follows the 'Left Border Case' defined by SD UHS
specification.
shows ACMD12 timings during read transfer.
Figure 18-28. Auto Command 12 Timings During Read Transfer
The Auto CMD12 arrival sent by the Host controller is not sensitive to the MMC bus configuration whether
it is DDR or standard transfer and whether it is a 1,4 or 8 bit bus width transfer.
3376
Multimedia Card (MMC)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated