16 dmac channel x [x = 0 ] control a register – Rainbow Electronics AT91CAP9S250A User Manual
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6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
26.5.16
DMAC Channel x [x = 0..3] Control A Register
Name: DMAC_CTRLAx [x = 0..3]
Access: Read/Write
Reset Value: 0x00000000
• BTSIZE
Buffer Transfer Size. The transfer size relates to the number of transfers to be performed, that is, for writes it refers to the
number of source width transfers to perform when DMAC is flow controller. For Reads, BTSIZE refers to the number of
transfers completed on the Source Interface. When this field is set to 0, the DMAC module is automatically disabled when
the relevant channel is enabled.
• SCSIZE
Source Chunk Transfer Size.
• DCSIZE
Destination Chunk Transfer size.
31
30
29
28
27
26
25
24
DONE
–
DST_WIDTH
–
–
SRC_WIDTH
23
22
21
20
19
18
17
16
–
DCSIZE
–
SCSIZE
15
14
13
12
11
10
9
8
BTSIZE
7
6
5
4
3
2
1
0
BTSIZE
SCSIZE value
Number of data transferred
000
1
001
4
010
8
011
16
100
32
101
64
110
128
111
256
DCSIZE
Number of data transferred
000
1
001
4
010
8
011
16
100
32