TLK111_14 Datasheet, PDF (16/110 Pages) Texas Instruments – PHYTER® Industrial Temperature 10/100Mbs Ethernet Physical Layer Transceiver

TLK111
SLLSEF8B – AUGUST 2013 – REVISED JANUARY 2014
www.ti.com
3.9 LED Interface
The TLK111 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.
Mode
1
2
3
LED_CFG[1]
(bit 6)
don't care
0
1
Table 3-3. LED Mode Select
LED_CFG[0]
(bit 5) or (pin 40)
1
0
0
LED_LINK
ON for Good Link
OFF for No Link
ON for Good Link
BLINK for Activity
ON for Good Link
BLINK for Activity
LED_SPEED
ON in 100Mbs
OFF in 10Mbs
ON in 100Mbs
OFF in 10Mbs
ON in 100Mbs
OFF in 10Mbs
LED_ACT
ON Pulse for Activity
OFF for No Activity
ON for Collision
OFF for No Collision
ON for Full Duplex
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.
AN_EN = 1
AN_1 = 1
AN_0 = 1
2.2 kW
470 W
2.2 kW
470 W
2.2 kW
470 W
VCC
B0315-01
Figure 3-6. AN Pin Configuration and LED Loading Example
16
Hardware Configuration
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