TLK111_14 Datasheet, PDF (13/110 Pages) Texas Instruments – PHYTER® Industrial Temperature 10/100Mbs Ethernet Physical Layer Transceiver

TLK111
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SLLSEF8B – AUGUST 2013 – REVISED JANUARY 2014
3.5 Auto-MDIX
The TLK111 device automatically determines whether or not it needs to cross over between pairs,
eliminating the requirement for an external crossover cable. If the TLK111 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, SW Strap register SWSCR1
(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.
3.6 PHY Address
The 5 PHY address inputs pins are shared with the RXD[3:0] pins and COL pin as shown in Table 3-2.
Table 3-2. PHY Address Mapping
PIN Number
42
43
44
45
46
PHYAD FUNCTION
PHYAD0
PHYAD1
PHYAD2
PHYAD3
PHYAD4
RXD FUNCTION
COL
RXD_0
RXD_1
RXD_2
RXD_3
Each TLK111 or port sharing an MDIO bus in a system must have a unique physical address. With 5
address input pins, the TLK111 can support PHY Address values 0 (<00000>) through 31 (<11111>). The
address-pin states are latched into an internal register at device power-up and hardware reset. Because
all the PHYAD[4:0] pins have weak internal pull-down/up resistors, the default setting for the PHY address
is 00001 (0x01h).
See Figure 3-3 for an example of a PHYAD connection to external components. In this example, the
PHYAD configuration results in address 00011 (0x03h).
PHYAD4 = 0 PHYAD3 = 0 PHYAD2 = 0 PHYAD1 = 1 PHYAD0 = 1
2.2 kW
VCC
Figure 3-3. PHYAD Configuration Example
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Hardware Configuration
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