PCI Programming Model
13-18
ADSP-BF535 Blackfin Processor Hardware Reference
PCI Programming Model
The PCI interface programming model includes memory-mapped control
and status registers, as well as memory-mapped PCI spaces (configuration,
I/O, and memory). The memory-mapped PCI spaces are described in
“Processor Core Access to PCI Space” on page 13-3
. This section
describes the memory-mapped control and status registers.
There are two sets of memory-mapped registers (MMRs) on the
ADSP-BF535 processor. The control and status registers clocked in the
internal ADSP-BF535 processor system clock domain are mapped into the
system MMR space. The control and status registers clocked in the PCI
clock domain are mapped into the PCI Configuration Registers memory
range (see the PCI memory map in
Figure 13-2 on page 13-5
). Each
group of registers is described in the sections that follow.
Bus Operation Ordering
Processor core accesses to the PCI interface always occur in the order that
the processor core initiated the system access. This implies:
• Since the processor core allows reads to occur before writes, with
respect to instruction order, the programmer must explicitly order
the load and store instruction by inserting an
SSYNC
instruction
between them in the cases where a PCI read must see the effect of a
previous PCI write. This is not required if the load and store
address and size are the same, for example, a write to a PCI Status
register followed by a read from the same register.
• ADSP-BF535 processor hardware does not enforce ordering among
the EAB, PAB, and EMB buses. Software must explicitly manage
any coherency issues among these buses. Shared resources should
be protected by software locks. With respect to program order,
EAB reads and PAB accesses are always completed in order, since
the core is stalled until they complete.
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...