ADSP-BF537 Blackfin Processor Hardware Reference
8-127
Ethernet MAC
u16 b_DMA2D:1;
/* 4
DMA mode */
u16 b_RESTART:1;
/* 5
Retain FIFO */
u16 b_DI_SEL:1;
/* 6
Data interrupt timing select */
u16 b_DI_EN:1;
/* 7
Data interrupt enabled */
u16 b_NDSIZE:4;
/* 8:11
Flex descriptor size */
u16 b_FLOW:3;
/* 12:14 Flow */
} ADI_DMA_CONFIG_REG;
A convenient way to handle the DMA properties in a “linked list” is to use
structures, because each set should be assigned to the appropriate DMA
descriptor.
shows a structure used to manage DMA descrip-
tors. Before jumping to the next descriptor, like 1A-1B-2A-2B-1C in
and
, the structure
ADI_DMA_CONFIG_REG
immediately loads to the DMA register before start-
ing its DMA transfer.
Listing 8-3. DMA Descriptor
typedef struct dma_descriptor {
struct dma_descriptor*
NEXT_DESC_PTR;
u32
START_ADDR;
ADI_DMA_CONFIG_REG
CONFIG;
} DMA_DESCRIPTOR;
The structure shown in
shows how it is possible to create a
“linked list” of DMAs. The
START_ADDR
points to the data and the
ADI_DMA_CONFIG_REG
sary settings.
Structures like these are convenient for handling Ethernet streams,
because they allow the programmer to simply call members of the struc-
ture instead of extracting meaningful items through array offsets. This
structure, shown in
, is mirrored in the Ethernet MAC header
with additional NoBytes.
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 ...