21154 PCI-to-PCI Bridge
Figure 3. 21154 Block Diagram
Secondary Data
Secondary Control
Secondary Data
Secondary
Arbiter
Secondary
Arbiter
Primary
and
Primary-
to-
Secondary
Control
Secondary
Data Path
Configuration
Registers
Clocks and
Reset
Secondary-
to-
Primary
Data Path
Primary
Request
and Grant
85%
Primary Data
Primary Control
Primary Data
LJ-04633.AI4
Table 1 describes the major functional blocks of the 21154.
Table 1. 21154 Function Blocks (Sheet 1 of 2)
Function Block
Description
PCI interface control logic. This block contains state machines and control
logic for the primary target interface, the primary master interface, the
secondary target interface, and the secondary master interface. This block
also contains logic that interfaces to the data path and the configuration
block.
Primary and Secondary Control
Data path for data received on the primary interface and driven on the
secondary interface. This block is used for write transactions initiated on
the primary PCI bus and for returning read data for read transactions
Primary-to-Secondary Data Path initiated on the secondary PCI bus. This block contains logic to store and,
for posted write transactions, to increment the address of the current
transaction. This block also performs bus command and configuration
address format translations.
4
Datasheet
INTEL [ INTEL ]
