System Interfaces
7-14
ADSP-BF535 Blackfin Processor Hardware Reference
In the case where the transfer is from on-chip to on-chip memory or from
off-chip to off-chip memory, the burst accesses cannot occur simultane-
ously. The transfer rate is then determined by adding each transfer plus an
additional cycle between each transfer.
Table 7-4
shows an example of two types of memory DMA transfers.
DAB Bus Agents (Masters)
All peripherals capable of sourcing a DMA access are masters on this bus,
as shown in the DAB arbitration priorities in
Table 7-2
. A single arbiter
supports a fixed priority arbitration policy for access to the DAB.
External Access Bus (EAB)
The EAB provides a way for the processor core and the Memory DMA
controller to directly access off-chip memory and the PCI memory space
to perform instruction fetches, data loads, data stores, and high through-
put memory-to-memory DMA transfers.
Table 7-4. Memory DMA Transfer Rates
Description of Transfer
Primary Burst of
8 Access in
SCLKs
Secondary Burst
of 8 Access in
SCLKs
Total SCLKs
Burst of 8 Transfer from SDRAM to
L1
(Off-chip to On-chip Memory Trans-
fer)
19 Cycles (L1)
16 Cycles
(SDRAM)
21 (19+2)
Burst of 8 Transfer from L2 to L1
(On-chip to On-chip Memory Trans-
fer)
19 Cycles (L1)
12 Cycles (L2)
33 (19+12+2)
Содержание ADSP-BF535 Blackfin
Страница 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Страница 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 908: ...SDRAM Controller External Bus Interface Unit B 36 ADSP BF535 Blackfin Processor Hardware Reference...