ADDR: the system memory address for an SDMA transfer. When the SDMMC stops an
SDMA transfer, this field points to the system address of the next contiguous data
position. This field can be accessed only if no transaction is executing (i.e., after
a transaction has stopped). Read operations during transfers may return an invalid
value. An interrupt can be generated to instruct the software to update this field.
Writing the next system address of the next data position restarts the SDMA
transfer.
ARG2: used with Auto CMD23 to set a 32-bit block count value to the CMD23 argument
while executing Auto CMD23. If Auto CMD23 is used with ADMA, the full 32-bit block
count value can be used. If Auto CMD23 is used without ADMA, the available block
count value is limited by SDMMC_BCR. In this case, 65535 blocks is the maximum
value.