General Hardware Design Considerations—Intel®IXP45X and Intel® IXP46X Product Line of Network Processors

Table 11. MAC Management Signal Recommendations NPE A,B,C

Name

Input/

Pull

 

Up/

Recommendations

Output

 

Down

 

 

 

 

 

 

 

 

 

 

 

NPE A,B,C

 

 

 

Management data output.

ETH_mdio

I/O

Yes

An external pull-up resistor of 1.5 KΩ is required on ETH_MDIO to properly quantify the

external PHYs used in the system. For specific implementation, see the IEEE 802.3

 

 

 

 

 

 

specification.

 

 

 

Should be pulled high through a 10-KΩresistor when not being utilized in the system.

 

 

 

 

ETH_mdc

I/O

No

NPE A,B,C

Management data clock.

 

 

 

 

 

 

 

3.5.2Device Connection, MII

Figure 8 is a typical example of an Ethernet PHY device interfacing to one of the MACs via the MII hardware protocol.

Figure 8. MII Interface Example

Intel®IXP46X

 

 

 

Product Line of

 

 

 

Network Processors

10/100

 

 

 

 

 

 

PHY

 

 

ETH_TXEN

TXEN

 

 

ETH_TXCLK

TXCLK

 

 

ETH_TXDATA[3:0]

TXDATA[3:0]

 

 

ETH_RXDV

RXDV

Magnetics

RJ45

ETH_RXCLK

RXCLK

 

 

ETH_RXDATA[3:0]

RXDATA[3:0]

 

 

ETH_COL

COL

25 MHz

 

ETH_CRS

CRS

 

 

 

VCC (3.3 V)

 

 

 

1.5 KΩ

 

 

ETH_MDIO

MDIO

 

 

ETH_MDC

MDC

 

 

MII Interface

 

 

 

 

 

 

B4101 -003

 

Intel® IXP45X and Intel® IXP46X Product Line of Network Processors

February 2007

HDD

Document Number: 305261; Revision: 004

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Intel IXP45X, IXP46X manual Device Connection, MII, MAC Management Signal Recommendations NPE A,B,C, Npe A,B,C