ADSP-BF537 Blackfin Processor Hardware Reference
5-95
Direct Memory Access
32-bit
DMAx_NEXT_DESC_PTR
register is copied into the
DMAx_CURR_DESC_
PTR
register. Then, during the descriptor fetch, the
DMAx_CURR_DESC_PTR
register increments after each element of the descriptor is read in.
L
In small and large descriptor list modes, the
DMAx_NEXT_DESC_PTR
register, and not the
DMAx_CURR_DESC_PTR
register, must be pro-
grammed directly via MMR access before starting DMA operation.
In descriptor array mode, the next descriptor pointer register is disre-
garded, and fetching is controlled only by the
DMAx_CURR_DESC_PTR
register.
Figure 5-17. Next Descriptor Pointer Registers
Table 5-20. Next Descriptor Pointer Register Memory-mapped Addresses
Register Name
Memory-mapped Address
DMA0_NEXT_DESC_PTR
0xFFC0 0C00
DMA1_NEXT_DESC_PTR
0xFFC0 0C40
DMA2_NEXT_DESC_PTR
0xFFC0 0C80
DMA3_NEXT_DESC_PTR
0xFFC0 0CC0
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
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
For Memory-
mapped
addresses, see
Reset = Undefined
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...