Datasheet

TLK110

SLLS901D –DECEMBER 2011–REVISED JANUARY 2014

www.ti.com

When auto negotiation has started, the TLK110 transmits FLP on one twisted pair and listens on the other,

thus trying to find out whether the other link partner supports the auto negotiation function as well. The

decision on what pair to transmit/listen depends on the MDI/MDI-X state. If the other link partner activates

auto negotiation, then the two parties begin to exchange their information. If the other link partner is a

legacy PHY or does not activate the auto negotiation, then the TLK110 uses the parallel detection

function, as described in IEEE802.3 chapters 40 and 28, to determine 10B-T or 100B-TX operation

modes.

5.4.2 Initialization and Restart

The TLK110 initiates the auto negotiation function if it is enabled through the configuration jumper options

AN_EN, AN_1 and AN_0 (pins 34,35,36) and one of the following events have happened:

1. Hardware reset de-assertion

2. Software reset (via register)

3. Auto negotiation restart (via register BMCR (0x0000h) bit 9)

4. Power-up sequence (via register BMCR (0x0000h) bit 11)

The auto-negotiation function is also initiated when the auto-negotiation enable bit is set in register BMCR

(0x0000h) bit 12 and one of the following events has happened:

1. Software restart

2. Transitioning to link_fail state, as described in IEEE802.3

To disable the auto-negotiation function during operation, clear register BMCR (0x0000h) bit 12. During

operation, setting/resetting this register does not affect the TLK110 operation. For the changes to take

place, issue a restart command through register BMCR (0x0000h) bit 9.

5.4.3 Configuration Bits

The auto-negotiation options can be configured through the configuration bits AN_EN, AN_1 and AN_0 as

described in Table 5-2. The configuration bits allow the user to disable/enable the auto negotiation, and

select the desirable advertisement features.

During hardware/software reset, the values of these configuration bits are latched into the auto-negotiation

registers and available for user read and modification.

Table 5-2. Auto-Negotiation Modes

AN_EN AN_1 AN_0 Forced Mode

0 0 0 10Base-T, Half-Duplex

0 0 1 10Base-T, Full-Duplex

0 1 0 100Base-TX, Half-Duplex

0 1 1 100Base-TX, Full-Duplex

AN_EN AN_1 AN_0 Advertised Mode

1 0 0 10Base-T, Half or Full-Duplex

1 0 1 100Base-TX, Half or Full-Duplex

1 1 0 10Base-T,Half-Duplex

100Base-TX, Half-Duplex

1 1 1 10Base-T,Half or Full-Duplex

100Base-TX, Half or Full-Duplex

Submit Documentation Feedback

Product Folder Links: TLK110