Hardware Reference Manual 347
Intel® IXP2800 Network Processor
PCI Unit
9.4.2.3.2 PCI Address Generation for Configuration Cycles
When a push/pull command bus master is accessing the PCI Bus to generate a configuration cycle,
the PCI address is generated based on the a Command Bus Master address as shown in Table128
and Figure 129:
9.4.2.3.3 PCI Address Generation for Special and IACK Cycles
The PCI address is undefined for special and IACK PCI cycles.
9.4.2.3.4 PCI Enables
The PCI byte-enables are generated based on the Command Bus Master instruction, and the PCI
unit does not change the states of the enables.
9.4.2.3.5 PCI Command
The PCI command is derived from the Command Bus Master address space map. The different
spaces supported are listed in Table129:
Table 128. Command Bus Master Configuration Transactions
Cycle Result
Type 1 Configuration Cycle Command Bus address bits [31:24] are equal to 0xDA
Type 0 Configuration Cycle Command Bus address bits [31:24] are equal to 0xDB.
Figure 129. PCI Address Generation for Command Bus Master to PCI Configuration Cycle
A9776-02
31 2627282930 232425 19202122 15161718 1214 13 891011 45673210
0000 0000 00
Intel XScale® Core Address[23:2]
Table 129. Command Bus Master Address Space Map to PCI
PCI Command Intel XScale® Core Address Space
PCI Memory 0xE000 0000 – 0xFFFF FFFF
Local CSR 0xDF00 0000 – 0xDFFF FFFF
Local Configuration Register 0xDE00 0000 – 0xDEFF FFFF
PCI Special Cycle/PCI IACK Read 0xDC00 0000 – 0xDDFF FFFF
PCI Type 1 Configuration Cycle 0xDB00 0000 – 0xDBFF FFFF
PCI Type 0 Configuration Cycle 0xDA00 0000 – 0xDAFF FFFF
PCI I/O 0xD800 0000 – 0xD8FF FFFF