TLK105 Datasheet, PDF (30/99 Pages) Texas Instruments – Industrial Temp, Single Port 10/100Mbs Ethernet Physical Layer Transceiver

TLK105
TLK106
SLLSEB8A – AUGUST 2012 – REVISED MARCH 2013
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5.3.4 Jabber Function
Jabber is a condition in which a station transmits for a period of time longer than the maximum permissible
packet length, usually due to a fault condition. The jabber function monitors the TLK10x output and
disables the transmitter if it attempts to transmit a packet of longer than legal size. A jabber timer monitors
the transmitter and disables the transmission if the transmitter is active for approximately 100ms.
When disabled by the Jabber function, the transmitter stays disabled for the entire time that the ENDEC
module's internal transmit enable is asserted. This signal must be de-asserted for approximately 500ms
(the unjab time) before the Jabber function re-enables the transmit outputs.
The Jabber function is only available and active in 10Base-T mode.
5.3.5 Automatic Link Polarity Detection and Correction
Swapping the wires within the twisted pair causes polarity errors. Wrong polarity affects the 10B-T PHYs.
The 100B-TX is immune to polarity problems because it uses MLT3 encoding. The 10B-T automatically
detects reversed polarity according to the received link pulses or data.
5.3.6 10Base-T Transmit and Receive Filtering
External 10Base-T filters are not required when using the TLK10x, because the required signal
conditioning is integrated into the device. Only isolation transformers and impedance matching resistors
are required for the 10Base-T transmit and receive interface. The internal transmit filtering ensures that all
the harmonics in the transmit signal are attenuated by at least 30dB.
5.3.7 10Base-T Operational Modes
The TLK10x has two basic 10Base-T operational modes:
• Half Duplex mode – In Half Duplex mode the TLK10x functions as a standard IEEE 802.3 10Base-T
transceiver supporting the CSMA/CD protocol.
• Full Duplex mode – In Full Duplex mode the TLK10x is capable of simultaneously transmitting and
receiving without asserting the collision signal. The TLK10x 10Mbs ENDEC is designed to encode and
decode simultaneously.
5.4 Auto Negotiation
The auto-negotiation function, described in detail in IEEE802.3 chapter 28, provides the means to
exchange information between two devices and automatically configure both of them to take maximum
advantage of their abilities.
5.4.1 Operation
Auto negotiation uses the 10B-T link pulses to encapsulate the transmitted data in a sequence of pulses,
also referred to as a Fast Link Pulses (FLP) burst. The FLP Burst consists of a series of closely spaced
10B-T link integrity test pulses that form an alternating clock/data sequence. Extraction of the data bits
from the FLP Burst yields a Link Code Word that identifies the operational modes supported by the remote
device, as well as some information used for the auto negotiation function’s handshake mechanism.
The information exchanged between the devices during the auto-negotiation process consists of the
devices' abilities such as duplex support and speed. This information allows higher levels of the network
(MAC) to send to the other link partner vendor-specific data (via the Next Page mechanism, see below),
and provides the mechanism for both parties to agree on the highest performance mode of operation.
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Architecture
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