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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—Ethernet MACs
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
Developer’s Manual
August 2006
230
Order Number: 306262-004US
6.1
Ethernet Coprocessor
Each Ethernet coprocessor contains a Media Access Controller, a transmit data FIFO,
and a receive data FIFO.
displays a block diagram of a single Ethernet coprocessor.
The Ethernet Coprocessor communicates to peripheral devices and the remainder of
the IXP45X/IXP46X network processors over four interfaces:
• APB Interface
• NPE Coprocessor Interface
• MII/SMII Interface
• Management Data Interface
6.1.1
Ethernet Coprocessor APB Interface
The APB interface is used to allow the Intel XScale processor to communicate directly
to configuration and control registers utilized by the Media Access Controller. The
Ethernet coprocessor’s APB interface will be used to configure the Ethernet MAC,
monitor Ethernet status, and configure the physical devices connected via the MII
interfaces. The physical devices connected to the MII interface will be configured using
the shared Management Data Interface.
6.1.2
Ethernet Coprocessor NPE Interface
The NPE Coprocessor Interface is used to communicate between the Ethernet
coprocessor and the NPE core. The NPE coprocessor interface will be used to transfer
incoming and outgoing data traffic to and from the NPE core. The NPE core — along
with other coprocessor — will take the Ethernet data and perform data manipulation,
forward the data to the SDRAM, and update the Queue Manager.
Figure 29.
Ethernet Coprocessor Interface
B4229-002
NPE
Coproc.
Interface
Transmit
FIFO
FIFO
Control
Register
Receive
FIFO
32 Bits to
Byte
Byte to 32
Bits
Transmit
Engine
MAC-
Control
Register
Receive
Engine
MII
Interface
MDIO
Interface
MDO
MDC
TX_DATA
RX_DATA
To APB
Bridge
To NPE
Core
Interface
Logic
APB
Interface
RXSTS*
TXSTS*
TX_DATA
RX_DATA
To PHY
Devices