Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Hoja De Datos

611

SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]

11063K–ATARM–05-Nov-13

Name: HSMCI_DMA

0xF0008050

Access: Read/Write

This register can only be written if the WPEN bit is cleared in 

.

This field indicates the number of discarded bytes when the DMA writes the first word of the transfer.

The CHKSIZE field indicates the number of data available when the DMA chunk transfer request is asserted.

0: DMA interface is disabled.

1: DMA Interface is enabled.

Note:

To avoid unpredictable behavior, DMA hardware handshaking must be disabled when CPU transfers are performed.

0: BLKLEN bytes are moved from the Memory Card to the system memory; two DMA descriptors are used when the transfer size 
is not a multiple of 4.

1: CEILING(BLKLEN/4) * 4 bytes are moved from the Memory Card to the system memory; only one DMA descriptor is used.

31

30

29

28

27

26

25

24

–

–

–

–

–

–

–

–

23

22

21

20

19

18

17

16

–

–

–

–

–

–

–

–

15

14

13

12

11

10

9

8

–

–

–

ROPT

–

–

–

DMAEN

7

6

5

4

3

2

1

0

–

CHKSIZE

–

–

OFFSET

0

1

1 data available

1

4

4 data available

2

8

8 data available

3

16

16 data available

4

32

32 data available