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.
Summary of Contents for ADSP-BF535 Blackfin
Page 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Page 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Page 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Page 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Page 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Page 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Page 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Page 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Page 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...