Descriptor Based DMA
9-10
ADSP-BF535 Blackfin Processor Hardware Reference
the DMA Configuration register. Bit 15, the
DBO
bit, of this register is
checked to determine whether the descriptor block is configured and
ready for use:
• If bit 15 is not set, the DMA channel stalls and waits until a pro-
cessor write occurs to the peripheral’s DMA Descriptor Ready
register (see
“Peripheral DMA Descriptor Ready Register” on
page 9-25
).
• This write triggers the DMA controller to recopy the DMA Con-
figuration Word from the current descriptor block into the DMA
Configuration register and to recheck bit 15.
• If bit 15 is set, the DMA channel fetches the remaining four ele-
ments (
BASE
+2,
BASE
+4,
BASE
+6,
BASE
+8) from the descriptor
block, loads them to the respective DMA control registers, and
begins DMA transfers.
• The status of the transfer sequence is updated every cycle in the
appropriate peripheral’s DMA status registers.
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...