Datasheet

Valid Data
LOW Quality Data / Link Loss
T1
First Link Failure
Occurrence
Link Drop
Signal
Link Loss
Indication
(Link LED)
TLK110
www.ti.com SLLS901D –DECEMBER 2011–REVISED JANUARY 2014
5.4.4 Next Page Support
The TLK110 supports the optional feature of the transmission and reception of auto-negotiation additional
(vendor specific) next pages.
If next pages are needed, the user must set register ANAR(0x0004h) bit 15 to '1'. The next pages are then
sent and received through registers ANNPTR(0x0007h) and ANLNPTR(0x0008h), respectively. The user
must poll register ANER(0x0006h) bit 1 to check whether a new page has been received, and then read
register ANLNPTR for the received next page's content. Only after register ANLNPTR is read may the
user write to register ANNPTR the next page to be transmitted. After register ANNPTR is written, new next
pages overwrite the contents of register ANLNPTR.
If register ANAR(0x0004h) bit 15 is set, then the next page sequence is controlled by the user, meaning
that the auto-negotiation function always waits for register ANNPTR to be written before transmitting the
next page.
If additional user-defined next pages are transmitted and the link partner has more next pages to send, it
is the user's responsibility to keep writing null pages (of value 0x2001) to register ANNPTR until the link
partner notifies that it has sent its last page (by setting bit 15 of its transmitted next page to zero).
5.5 Link Down Functionality
The TLK110 includes advanced link-down capabilities that support various real-time applications. The link-
down mechanism of the TLK110 is configurable and includes enhanced modes that allow extremely fast
reaction times to link-drops.
Figure 5-3. TLK110 Link Loss Mechanism
As described in Figure 5-3, the TLK110 link loss mechanism is based on a time window search period, in
which the signal behavior is monitored. The T1 window is set by default to reduce typical link-drops to less
than 1ms.
The TLK110 supports enhanced modes that shorten the window called Fast Link Down mode. In this
mode, which can be configured in Software Strap Control Register 3 (SWSCR3), address 0x000B, bits
3:0, the T1 window is shortened significantly, in most cases less than 10µs. In this period of time there are
several criteria allowed to generate link loss event and drop the link:
1. Count RX Error in the MII interface: When a predefined number of 32 RX Error occurrences in time
window of 10µs is reached the link will drop.
2. Count MLT3 Errors at the signal processing output (100BT uses MLT3 coding, and when a violation of
this coding is detected, an MLT3 error is declared). When a predefined number of 20 errors
occurrences in 10µs is reached the link will drop.
3. Count Low Signal Quality Threshold crossing (When the signal quality is under a certain threshold that
allows proper link conditions). When a predefined number of 20 occurrences in 10µs is reached, the
link will drop.
4. Signal/Energy loss indications. When Energy detector indicates Energy Loss, the link will be dropped.
Typical reaction time is 10µs.
Copyright © 2011–2014, Texas Instruments Incorporated Architecture 35
Submit Documentation Feedback
Product Folder Links: TLK110