RM0319 datasheet(191/368 Pages) STMICROELECTRONICS

191 / 368 page

RM0319

MMC-SD card/SDIO controller

Doc ID 022640 Rev 3

191/368

Create Descriptor table for ADMA in the system memory

Set the Descriptor address for ADMA in the ADMA System Address register.

Set the value corresponding to the Block Size register.

Set the value corresponding to the Block Count register. If the Block Count Enable in

the Transfer Mode register is set to logic ‘1’, the total data length can be designated by

the Block Count register and the Descriptor Table. These two parameters must indicate

the same data length. However, the transfer length is limited by the 16-bit Block Count

total data length is designated not by the Block Count register, but by the Descriptor

Table. In this case, ADMA reads more data than the length programmed in the

descriptor from the SD card. The read operation of extra data is aborted

asynchronously and the extra read data is discarded when the ADMA is completed.

Set the argument value to the Argument register.

Set the value to the Transfer Mode register. The host driver determines Multi/Single

Block Select, Block Count Enable, Data Transfer Direction, Auto CMD12 Enable and

DMA Enable.

Set the value to the Command register.

Wait for the Command Complete Interrupt.

Write logic ‘1’ to the Command Complete in the Normal Interrupt Status register to

clear this bit.

10. Read the Response register and get necessary information about the issued

command.

11. Wait for the Transfer Complete Interrupt and ADMA Error Interrupt.

12. If Transfer Complete is set to logic ‘1’, go to Step (13), else if ADMA Error Interrupt is

set to logic ‘1’, so go to Step (14).

13. Write logic ‘1’ to the Transfer Complete Status in the Normal Interrupt Status register to

clear this bit.

14. Write logic ‘1’ to the ADMA Error Interrupt Status in the Error Interrupt Status register to

clear this bit.

15. Abort ADMA operation. SD card operation should be stopped by issuing abort

command.

RM0319 датащи(PDF) 191 Page - STMicroelectronics