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

3.5.1Signal Interface MII

Table 8.

MII NPE A Signal Recommendations

 

 

 

 

 

 

 

 

 

 

 

Input/

Pull

 

 

 

Name

 

Up

Recommendations

 

 

 

Output

 

 

 

 

Down

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Transmit Clock.

 

ETHA_TXCLK

 

I

Yes

When this interface/signal is enabled and is not being used in a system design, the

 

 

 

 

 

 

interface/signal should be pulled high with a 10-KΩresistor.

 

 

 

 

 

 

ETHA_TXDATA[3:0]

O

No

Transmit Data.

 

 

 

 

 

 

 

ETHA_TXEN

 

O

No

Transmit Enable.

 

 

 

 

 

 

 

 

 

 

 

 

 

Receive Clock.

 

ETHA_RXCLK

 

I

Yes

When this interface/signal is enabled and is not being used in a system design, the

 

 

 

 

 

 

interface/signal should be pulled high with a 10-KΩresistor.

 

 

 

 

 

 

 

 

 

 

 

 

 

Receive Data.

 

ETHA_RXDATA[3:0]

I

Yes

When this interface/signal is enabled and is not being used in a system design, the

 

 

 

 

 

 

interface/signal should be pulled high with a 10-KΩresistor.

 

 

 

 

 

 

 

 

 

 

 

 

 

Receive Data Valid.

 

ETHA_RXDV

 

I

Yes

When this interface/signal is enabled and is not being used in a system design, the

 

 

 

 

 

 

interface/signal should be pulled high with a 10-KΩresistor.

 

 

 

 

 

 

 

 

 

 

 

 

 

Collision Detect.

 

ETHA_COL

 

I

Yes

If operating in a full duplex mode and there is no requirement to use the Collision

 

 

 

 

 

 

Detect signal, then the pin must be pulled low with a 10-KΩresistor.

 

 

 

 

 

 

 

 

 

 

 

 

 

Carrier Sense.

 

ETHA_CRS

 

I

Yes

When this interface/signal is enabled and is not being used in a system design, the

 

 

 

 

 

 

interface/signal should be pulled high with a 10-KΩresistor.

 

 

 

 

 

 

 

 

Notes:

 

 

 

 

 

 

1.

Features disabled/enabled by Soft Fuse must be done during the boot-up sequence. A feature cannot be enabled after

 

 

being disabled without asserting a system reset.

 

2.

Features disabled by a specific part number, do not require pull-ups or pull-downs. Therefore, all pins can be left

 

 

unconnected.

 

 

 

 

3.

Features enabled by a specific part number — and required to be Soft Fuse-disabled, as stated in Note 1 — only require

 

 

pull-ups or pull-downs in the clock-input signals.

 

 

 

 

 

 

 

Table 9.

MII NPE B Signal Recommendations (Sheet 1 of 2)

 

 

 

 

 

 

 

 

 

Input/

Pull

 

 

Name

 

Up/

Recommendations

 

 

Output

 

 

 

Down

 

 

 

 

 

 

 

 

 

 

 

 

Transmit Clock.

 

ETHB_TXCLK

 

I

Yes

When this interface/signal is enabled and is not being used in a system design, the

 

 

 

 

 

interface/signal should be pulled high with a 10-KΩresistor.

 

 

 

 

 

 

ETHB_TXDATA[3:0]

O

No

Transmit Data.

 

 

 

 

 

 

 

ETHB_TXEN

 

O

No

Transmit Enable.

 

 

 

 

 

 

 

 

 

 

 

Receive Clock.

 

ETHB_RXCLK

 

I

Yes

When this interface/signal is enabled and is not being used in a system design, the

 

 

 

 

 

interface/signal should be pulled high with a 10-KΩresistor.

 

 

 

 

 

 

 

 

 

 

 

Receive Data.

 

ETHB_RXDATA[3:0]

I

Yes

When this interface/signal is enabled and is not being used in a system design, the

 

 

 

 

 

interface/signal should be pulled high with a 10-KΩresistor.

 

 

 

 

 

 

 

 

 

 

 

Receive Data Valid.

 

ETHB_RXDV

 

I

Yes

When this interface/signal is enabled and is not being used in a system design, the

 

 

 

 

 

interface/signal should be pulled high with a 10-KΩresistor.

 

 

 

 

 

 

 

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 Signal Interface MII, MII NPE a Signal Recommendations, MII NPE B Signal Recommendations Sheet 1