TLK105 datasheet(24/99 Pages) TI

24 / 99 page

Scrambler

NRZ to NRZI

Convertor

MLT-3

encoding

D/A

Convertor

100Base TX

Line Driver

4B/5B

encoding

Manchester

encoding

10Base T

Line Driver

10Base T

Filter

Manchester

decoding

4B/5B

decoding

DeScrambler

NRZI to NRZ

Convertor

MLT-3

decoding

DSP (BLW

Correction,

Adapt. Equal)

ADC (Filter,

Amplifierl)

10Base T

Receive

Filter

Transmit

Receive

MII

100Base TX

10Base-T

Adv.

Link Monitor

TLK105

TLK106

SLLSEB8A – AUGUST 2012 – REVISED MARCH 2013

www.ti.com

Architecture

The TLK10x Fast Ethernet transceiver is a physical layer core for Ethernet 100Base-TX and 10Base-T

applications. The TLK10x contains all the active circuitry required to implement the physical layer functions

to transmit and receive data on standard CAT 3 and 5 unshielded twisted pair. The core supports the

IEEE 802.3 Standard Fast Media Independent Interface (MII), as well as the Reduced Media Independent

Interface (RMII), for direct connection to a MAC/Switch port.

The TLK10x uses mixed signal processing to perform equalization, data recovery and error correction to

achieve robust and low power operation over the existing CAT 5 twisted pair wiring. The TLK10x

architecture not only meets the requirements of IEEE802.3, but maintains a high level of margin over the

IEEE requirements for NEXT, Alien and External noise.

Figure 5-1. PHY Architecture

5.1

100Base-TX Transmit Path

In 100Base-TX, the MAC feeds the 100Mbps transmit data in 4-bit wide nibbles through the MII interface.

The data is encoded into 5-bit code groups, encapsulated with control code symbols and serialized. The

control-code symbols indicate the start and end of the frame and code other information such as transmit

errors. When no data is available from the MAC, IDLE symbols are constantly transmitted. The serialized

bit stream is fed into a scrambler. The scrambled data stream passes through an NRZI encoder and then

through an MLT3 encoder. Finally, it is fed to the DAC and transmitted through one of the twisted pairs of

the cable.

5.1.1

MII Transmit Error Code Forwarding

According to IEEE 802.3:

“If TX_EN is de-asserted on an odd nibble boundary, PHY should extend TX_EN by one TX_CLK

cycle and behave as if TX_ER were asserted during that cycle”.

The TLK10x supports Error Forwarding in MII transmission from the MAC to the PHY. Error forwarding

allows adding information to the frame to be used as an error code between the 2 MACs. The error code

informs the receiving MAC on the link partner side of the reason for the error from the transmitting side. If

the MAC transmits an odd number of nibbles, an additional error nibble is added to the transmitted frame

just before the end of the transmission.

To turn off Transmit Error Forwarding, write to bit 1 of register CR2 (0x000A). If Error Forwarding is

disabled, delivered packets contain either odd or even numbers of nibbles.

In Figure 5-2, Error Code Forwarding functionality is illustrated. The wave diagram demonstrates MAC’s

transmitted signals in one side and MAC’s reception signals on link partner side.

Architecture

Submit Documentation Feedback

Product Folder Links: TLK105 TLK106

TLK105 Datasheet(PDF) 24 Page - Texas Instruments

TLK105 Datasheet(HTML) 24 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

Datasheet Download

Link URL