Intel IXP2800 9.2.2 IXP2800 Network Processor Initialization

Hardware Reference Manual 323
Intel® IXP2800 Network Processor
PCI Unit
PCI functions not supported by the PCI Unit include:
•IO Space response as a target
•Cacheable memory
•VGA palette snooping
•PCI Lock Cycle
•Multi-function devices
•Dual Address cycle
9.2.2 IXP2800 Network Processor Initialization
When the IXP2800 Network Processor is a target, the internal CSR, DRAM, or SRAM address is
generated when the PCI address matches the appropriate base address register. The window sizes to
the SRAM and DRAM Base Address Registers (BARs) can be optionally set by PCI_SWIN and
PCI_DWIN strap pins or mask registers depending on the state of the PROM_BOOT signal.
There are two initialization modes supported. They are determined by the PROM_BOOT signal
sampled on the de-assertion edge of Chip Reset. If PROM_BOOT is asserted, then there is a boot
prom in the system. The Intel XScale® core will boot from the prom and be able to program the
BAR space mask registers. If PROM_BOOT is not asserted, the Intel XScale® core is held in reset
and the BAR sizes are determined by strap pins.
0xC Memory Read
Multiple
Aliased as Memory Read except
SRAM accesses where the number
of Dwords to read is given by the
cache line size.
Supported
0xD Reserved — —
0xE Memory read line
Aliased as Memory Read except
SRAM accesses where the number
of Dwords to read is given by the
cache line size.
Supported
0xF Memory Write and
Invalidate Aliased as Memory Write. Not Supported
Table 119. PCI Commands (Sheet 2 of 2)
C_BE_L Command
Support
Target Initiator