SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
Depending on whether DMA (optional) is used or not, there are two execution methods.
In addition, the sequences for SD transfers are classified into following three kinds according to how the number of blocks is specified:
(1) Single Block Transfer: The number of blocks is specified to the Host Controller before the transfer. The number of blocks specified is always one.
(2) Multiple Block Transfer: The number of blocks is specified to the Host Controller before the transfer. The number of blocks specified shall be one or more.
(3) Infinite Block Transfer: The number of blocks is not specified to the Host Controller before the transfer. This transfer is continued until an abort transaction is executed. This abort transaction is performed by CMD12 in the case of a SD memory card and by CMD52 in the case of a SDIO card.