Intel 82555 manual Auto 10/100 Mbps Speed Selection, Adapter Mode Addresses

Models: 82555

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Networking Silicon — 82555

The figure below illustrates an 82557/82555/PHY-T4 solution in a block diagram.

 

 

T4

 

 

 

adv

 

 

 

82555

Common

 

 

 

 

 

 

Magnetics

PCI BUS

 

fdx_n

 

 

MII

slave tri

 

 

 

82557

listat n

 

 

 

 

PHY-T4

 

 

 

 

3669

Figure 8. Combination Card Example

4.6Auto 10/100 Mbps Speed Selection

The MAC may either allow the 82555 to automatically select its operating speed or force the 82555 into 10 Mbps or 100 Mbps mode. The Management Data Interface (MDI) can control the 82555 speed mode.

The 82555 autoselect function determines the operation speed of the media based on the link integrity pulses it receives. If no Fast Link Pulses (FLPs) are detected and Normal Link Pulses (NLPs) are detected, the 82555 defaults to 10 Mbps operation. If the 82555 detects a speed change, it dynamically changes its transmit clock and receive clock frequencies to the appropriate value. This change takes a maximum of five milliseconds.

4.7Adapter Mode Addresses

In DTE (adapter) mode, the 82555 supports addresses 0, 1, 2, and 3 through the pins PHYA1 and PHYA0. Four addresses are sufficient in the case of a combination adapter having three PHYs. For switch applications, the T4ADV signal should be de-asserted to allow all 32 addresses to be available in repeater mode.

Datasheet

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Intel 82555 manual Auto 10/100 Mbps Speed Selection, Adapter Mode Addresses