Datasheet

LED_LINK
LED_SPEED LED_ACT/COL
470 W 470 W470 W
2.2 kW 2.2 kW2.2 kW
VCC
AN_EN = 1 AN_1 = 1 AN_0 = 1
B0315-01
TLK110
SLLS901D –DECEMBER 2011–REVISED JANUARY 2014 www.ti.com
3.9 LED Interface
The TLK110 supports three configurable Light Emitting Diode (LED) pins. The device supports three LED
configurations: Link, Speed, and Activity. Functions are multiplexed among the LEDs into three modes.
The LEDs can be controlled by configuration pin and-or internal register bits. Bits 6:5 of the PHY Control
register (PHYCR) selects the LED mode as described in Table 3-3.
Table 3-3. LED Mode Select
LED_CFG[1] LED_CFG[0]
Mode LED_LINK LED_SPEED LED_ACT
(bit 6) (bit 5) or (pin 40)
ON for Good Link ON in 100Mbs ON Pulse for Activity
1 don't care 1
OFF for No Link OFF in 10Mbs OFF for No Activity
ON for Good Link ON in 100Mbs ON for Collision
2 0 0
BLINK for Activity OFF in 10Mbs OFF for No Collision
ON for Good Link ON in 100Mbs ON for Full Duplex
3 1 0
BLINK for Activity OFF in 10Mbs OFF for Half Duplex
The LED_LINK pin in Mode 1 indicates the link status of the port. The LED is OFF when no link is present.
In Mode 2 and Mode 3 it is ON to indicate that the link is good; BLINK indicates that activity is present on
either transmit or receive channel. Bits 10:9 of the LEDCR register (0x18) control the blink rate. The
default blink rate is 5Hz.
The LED_SPEED pin indicates the data rate of the port, 10Mbs or 100Mbs. This LED is ON when the
device is operating in 100Mbs operation. The functionality of this LED is independent of mode selected.
The LED_ACT pin in Mode 1 indicates the presence of either transmit or receive activity. The LED is ON
(Pulse) for Activity and OFF for No Activity. In mode 2 this pin indicates the collision status of the port. The
LED is ON when there is a collision and OFF when there is no collision. In mode 3 this pin indicates the
Duplex status of operation. The LED is ON for Full Duplex and OFF for Half Duplex.
Bits 8:6 of the LEDCR register define the polarity of the signals on the LED pins.
Because the Auto-Negotiation (AN) configuration options share the LED output pins, the external
components required for configuration-pin programming and those for LED usage must be considered in
order to avoid contention.
See Figure 3-6 for an example of AN_0, AN_1, AN_EN connections to external components. In this
example, the configuration results in Auto-Negotiation with 10/100 Full-Duplex advertised.
Figure 3-6. AN Pin Configuration and LED Loading Example
16 Hardware Configuration Copyright © 2011–2014, Texas Instruments Incorporated
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