User's Manual

Table Of Contents
HSMMC CONTROLLER S3C2450X RISC MICROPROCESSOR
21-12
4.11 TRANSACTION CONTROL WITH DATA TRANSFER USING DAT LINE
Depending on whether DMA (optional) is used or not, there are two execution methods. The sequence not using
DMA is shown in Figure 21-11 and the sequence using DMA is shown in Figure 21-12.
In addition, the sequences for SD transfers are basically 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(Stop Command) in the case
of a SD memory card, and by CMD52(IO_RW_DIRECT) in the case of a SDIO card.