DMA Registers
7-82
ADSP-BF50x Blackfin Processor Hardware Reference
In descriptor array mode, the next descriptor pointer register is disre-
garded, and fetching is controlled only by the
DMAx_CURR_DESC_PTR
register.
DMA Current Descriptor Pointer Registers
(DMAx_CURR_DESC_PTR/
MDMA_yy_CURR_DESC_PTR)
The 32-bit
DMAx_CURR_DESC_PTR
register, shown in
Figure 7-17
, contains
the memory address for the next descriptor element to be loaded. For
FLOW
mode settings that involve descriptors (
FLOW
= 4, 6, or 7), this register is
used to read descriptor elements into appropriate MMRs before a DMA
work block begins. For descriptor list modes (
FLOW
= 6 or 7), this register
is initialized from the
DMAx_NEXT_DESC_PTR
register before loading each
descriptor. Then, the address in the
DMAx_CURR_DESC_PTR
register incre-
ments as each descriptor element is read in.
When the entire descriptor has been read, the
DMAx_CURR_DESC_PTR
regis-
ter contains this value:
Descriptor Start A (2x Descriptor Size) (# of elements)
Figure 7-16. DMA Next Descriptor Pointer Registers
31 30
29 28
27 26
25 24
23 22
21 20
19
18 17 16
X
Next Descriptor
Pointer[31:16]
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
DMA Next Descriptor Pointer Registers
(DMAx_NEXT_DESC_PTR/MDMA_yy_NEXT_DESC_PTR)
R/W prior to enabling channel; RO after enabling channel
15 14
13 12
11 10
9
8
7
6
5
4
3
2
1
0
X
Next Descriptor
Pointer[15:0]
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Reset = Undefined
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...