SWRU626 December 2025 CC3501E , CC3551E
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. SDMMC only follows the 'Left Border Case' defined by SD UHS specification.
Figure 20-19 shows ACMD12 timings during read transfer.
Figure 20-19 Auto Command 12 Timings During
Read TransferThe Auto CMD12 arrival sent by the Host controller is not sensitive to the SDMMC bus configuration whether it is a 1 or 4 bit bus width transfer.