TLK105 Datasheet, PDF (10/99 Pages) Texas Instruments – Industrial Temp, Single Port 10/100Mbs Ethernet Physical Layer Transceiver

TLK105
TLK106
SLLSEB8A – AUGUST 2012 – REVISED MARCH 2013
www.ti.com
3.4 Auto-Negotiation
The TLK10x device auto-negotiates to operate in 10Base-T or 100Base-TX. With Auto-Negotiation
enabled, the TLK10x negotiates with the link partner to determine the speed and duplex mode. If the link
partner cannot Auto-Negotiate, the TLK10x device enters parallel-detect mode to determine the speed of
the link partner. Parallel-detect mode uses fixed half-duplex mode.
The TLK10x supports four different Ethernet protocols (10Mbs Half-Duplex, 10Mbs Full-Duplex, 100Mbs
Half-Duplex, and 100Mbs Full-Duplex). Auto-Negotiation selects the highest performance protocol based
on the advertised ability of the Link Partner. Control the Auto-Negotiation function within the TLK10x by
internal register access according to the IEEE specification.
Alternatively, control the HD-FD functionality by configuring the AN_0 pins. The state of AN_0 selects full
or half duplex mode, both in Auto-negotiation or force 100/10 mode as given in Table 3-1. The state of
AN_0 upon power-up/reset, determines the state of bits [8:5] of the ANAR register (0x04h).
Auto-Negotiation advertises ANEN, 100BT by default. Full-Duplex or Half-Duplex configuration is available
through the AN_0 bit. Internal register access configures the device for a specific mode.
Table 3-1. Auto-Negotiation Modes
AN_0
0
1
Forced Mode
10Base-T, Half-Duplex
100Base-TX, Half-Duplex
10Base-T, Half or Full-Duplex
100Base-TX, Half or Full-Duplex
Internal register access controls the Auto-Negotiation function, as defined by the IEEE 802.3u
specification. For further detail regarding Auto-Negotiation, see Clause 28 of the IEEE 802.3u
specification.
3.5 Auto-MDIX
The TLK10x device automatically determines whether or not it needs to cross over between pairs,
eliminating the requirement for an external crossover cable. If the TLK10x interoperates with a device that
implements MDI/MDIX crossover, a random algorithm as described in IEEE 802.3 determines which
device performs the crossover.
Auto-MDIX is enabled by default and can be configured via pin strap, control register CR1 (0x09h), bit 14
or via register PHYCR (0x19h), bit 15.
The crossover can be manually forced through bit 14 of the PHYCR (0x19h) register. Neither Auto-
Negotiation nor Auto-MDIX is required to be enabled in forcing crossover of the MDI pairs.
Auto-MDIX can be used in the forced 100Base-TX mode. Because in modern networks all the nodes are
100Base-TX, having the Auto-MDIX working in the forced 100Base-TX mode resolves the link faster
without the need for the long Auto-Negotiation period.
10
Hardware Configuration
Copyright © 2012–2013, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: TLK105 TLK106