ADSP-BF535 Blackfin Processor Hardware Reference
13-17
PCI Bus Interface
The ADSP-BF535 processor can also cause a reset to the PCI using the
two bits provided in the
PCI_CTL
register. The first bit is the RST to PCI
Enable bit, which is the output enable on the
PCI_RST
pad. The second bit
is the RST to PCI bit, which when set, causes the
PCI_RST
signal to be
asserted. Resetting the PCI system in this manner has the same effect on
the PCI core and surrounding logic as the
PCI_RST
input signal. The logic
of the PCI module does not restrict the ADSP-BF535 processor from
causing a
PCI_RST
in device mode, but doing this is recommended only
when the ADSP-BF535 processor is in host mode.
Note all PCI signals are active low, but the bits in the
PCI_CTL
and the
PCI_STAT
registers are active high. This means that setting the RST to PCI
bit in the
PCI_CTL
register asserts
PCI_RST
, and the PCI Reset bit in the
PCI_STAT
register is set when the
PCI_RST
line is asserted.
Interrupt Behavior and Control
All four interrupt lines from PCI (
INTA-INTD
) have associated sticky status
bits in the
PCI_STAT
register. Whenever one of these interrupt lines is
asserted, the appropriate bit is set and an interrupt is generated if masked
to do so in the
PCI_ICTL
register. These bits are valid in host or device
mode, but are most useful when the ADSP-BF535 processor is acting as
the system host.
The
INTA
interrupt line is defined as an input/output because the
ADSP-BF535 processor is capable of generating an interrupt to the system
processor by setting the INTA to PCI bit in the PCI Bridge Control regis-
ter. This bit asserts
INTA
in device mode or host mode, but it is most
useful in device mode. In host mode it makes more sense to use a core
interrupt, if necessary.
Note all PCI signals are active low, but the bits in the
PCI_CTL
and the
PCI_STAT
registers are active high. So setting the INTA to PCI bit asserts
the
INTA
signal and the
INTA-INTD
bits are set when the corresponding line
is asserted.
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...