IBM PowerPC 405GP User Manual

17.4 PCI Bridge Transaction Handling
The following sections discuss PCI bridge transactions and completion ordering.
17.4.1 PLB-to-PCI Transaction Handling
This section describes how the PCI bridge responds to read and write requests from a PLB master.
The
PCI bridge decodes and accepts PLB transactions to different address ranges resulting in the
generation of memory,
liD, configuration, interrupt acknowledge and special cycles on the PCI bus.
Table 17-5. Transaction Mapping: PLB -> PCI
PLB Transaction
PCI Transaction
PLB Master ~ Bridge Bridge Mapping and Bridge (PCI Master Interface) ~ PCI
(PLB Slave Interface)
Qualifications Target
Single-beat 1
~ a-byte Read
64KB or 56MB PCI I/O I/O Read
address range
Single-beat 1
~ a-byte Write
64KB or 56MB PCI I/O I/O Write
address range
Single-Beat 1
~ a-byte Read Access to PCICO_CFGDATA
Configuration Read (Type 0, 1)
register
Single-Beat 1
~ a-byte Write
Access to PCICO_CFGDATA Configuration Write (Type
0, 1)
register
Single-Beat 1
~ a-byte Read
PLB address decodes to Memory Read
PMMO, PMM1, or PMM2,
nonprefetchable
Burst Read
PLB address decodes to Memory Read
PMMO, PMM1, or PMM2,
nonprefetchable
PLB 4-word and a-word Line Reads
PLB address decodes to Memory Read Line
PMMO, PMM1, or PMM2
Single-Beat 1
~ 4-byte Read
PLB address decodes to Memory Read Multiple
PMMO, PMM1, or PMM2,
nonprefetchable
Burst Read
PLB address decodes to Memory Read Multiple
PMMO, PMM1, or PMM2,
nonprefetchable
Single-Beat 1
~ 4-byte Write
PLB address decodes to Memory Write
PMMO, PMM1, or PMM2
Burst Write
PLB address decodes to Memory Write
PMMO, PMM1, or PMM2
Single-Beat 1
~ 4-byte Read
Address
OxFEDOOOOO Interrupt Acknowledge
Single-Beat 1
~ 4-byte Write
Address
OxFEDOOOOO Special Cycle
-
Not supported Memory Write and Invalidate
-
Not supported
Memory Write Line
17.4.1.1 PCI Master Commands
The type of cycle generated to the PCI bus depends on the PLB address, the type of PLB transfer,
and the data size. The
following sections describe the transaction types supported and outlines the
translation of commands from one bus to the other.
17-10 PPC405GP User's Manual
Preliminary

IBM PowerPC 405GP Specifications

General

Brand	IBM
Model	PowerPC 405GP
Category	Computer Hardware
Language	English