Atmel Evaluation Kit AT91SAM9X35-EK AT91SAM9X35-EK Data Sheet

Product codes
AT91SAM9X35-EK
Page of 1301
625
SAM9X35 [DATASHEET]
11055E–ATARM–10-Mar-2014
34.14.16  HSMCI DMA Configuration Register
Name: HSMCI_DMA
Address:
0xF0008050 (0), 0xF000C050 (1)
Access: Read-write
This register can only be written if the WPEN bit is cleared in 
.
• OFFSET: DMA Write Buffer Offset
This field indicates the number of discarded bytes when the DMA writes the first word of the transfer.
• CHKSIZE: DMA Channel Read and Write Chunk Size 
The CHKSIZE field indicates the number of data available when the DMA chunk transfer request is asserted.
 
• DMAEN: DMA Hardware Handshaking Enable
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.
• ROPT: Read Optimization with padding
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.
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ROPT
DMAEN
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1
0
CHKSIZE
OFFSET
Value
Name
Description
0
1
1 data available
1
4
4 data available
2
8
8 data available
3
16
16 data available
Reserved