Host Mode Operation
13-14
ADSP-BF535 Blackfin Processor Hardware Reference
Inbound Transactions (ADSP-BF535 Processor as
PCI Target)
Inbound transactions in host mode are accomplished by the same method
as in device mode. However, only memory accesses are claimed by the PCI
interface, and PCI memory space is mapped directly to ADSP-BF535
processor memory space. In other words, the ADSP-BF535 processor
memory map becomes the system memory map, and all resources in the
ADSP-BF535 processor memory map that are accessible from PCI lie at
the same address in PCI memory space. In host mode, a register
(
PCI_HMCTL
) is provided at the bottom of the PCI configuration registers
to configure which ADSP-BF535 processor resources are accessible from
PCI.
This register contains four enable bits, one for each region of
ADSP-BF535 processor space that can be used for PCI accesses in host
mode. The regions are system MMRs, L2 memory, asynchronous mem-
ory, and SDRAM. The register also contains two size fields, one for the
asynchronous memory and one for SDRAM memory, that specify how
much of each of these spaces is available to PCI. For the asynchronous
memory region, the size field is 2 bits and specifies the number of contig-
uous banks that are accessible. For the SDRAM region, the size field is 5
bits and specifies the number of contiguous 32 MB blocks that are accessi-
ble. These size fields are 0 based. This means, for example, enabling
asynchronous memory and leaving its size field all 0s results in a single
bank enabled. The size field can be thought of as the “size minus one”
field. You must write a 0 to the enable bit to completely disable asynchro-
nous memory or SDRAM. This functionality allows the ADSP-BF535
processor to prevent the PCI from accessing space above the valid memory
region when SDRAM or asynchronous memory is not fully populated. It
also allows the ADSP-BF535 processor to protect upper parts of SDRAM
or asynchronous memory from PCI accesses. Any space between these 4
regions is available for assignment to PCI devices during configuration.
Any space made available by disabling one of these regions or by sizing
down one of the RAM regions is also available for assignment to PCI
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...