82562GT Datasheet, PDF (24/46 Pages) Intel Corporation – 10/100 Mbps Platform LAN Connect (PLC)

82562GT — Networking Silicon
5.4.1
Auto Plugging Detection
The 82562GT senses the link all the time. If it detects loss of any link activity for more than 6.6
seconds, it indicates to the Media Access Controller (MAC) an “unplugged state” by resetting the
SQL LAN Connect control bit. If the 82562GT is in reduced power mode and link activity is
detected, the 82562GT notifies the MAC (in less than 1 second) that it is in a “plugged state” by
setting the SQL LAN Connect control bit. Link activity detection is based on energy detection.
5.4.2
Dynamic Reduced Power
The 82562GT can be configured to support dynamic reduced power. In the dynamic reduced power
mode, the 82562GT transitions to reduced power mode when an unplugged state is detected. The
82562GT only returns to full power if the reduced power bit on the LAN Connect is reset and a
plugged state is detected. However, if the 82562GT is not configured to support dynamic reduced
power, the 82562GT operates according to the LAN Connect power-down bit (in other words, the
82562GT operates in reduced power mode only if the LAN Connect power-down bit is set).
5.4.3
Configuration
The dynamic reduced power mode is configured through bit 13 of register 16. The default value is
disabled (0). The status of the 82562GT is read through bits 10:9 of register 16. When the 82562GT
is in reduced power mode, these two bits are set to 1b.
Table 6. Register 16 (10 Hexadecimal): PLC Status, Control and Address Data
Bit
13
Name
Dynamic Reduced Power Down
10
100BASE-TX Power Down
9
10BASE-T Power Down
Description
Read/Write
0 = Automatic reduced power down
enabled
1 = Automatic reduced power down
disabled (default)
Read/Write
The 100BASE-TX Power Down bit indicates
the power state.
0 = Normal operation (default)
1 = Power down
Read Only
The 10BASE-T Power Down bit indicates
the power state.
0 = Normal operation (default)
1 = Power down
Read Only
The 82562GT PLC can enter a reduced power state manually through bit 11 of register 0. This bit is
ORed with the LAN Connect power down bit, which enables the 82562GT to enter a reduced
power state.
Table 7. Register 0: Control Data
Bit
11
Name
Reduced Power Down
Description
Read/Write
0 = Reduced power down disabled (normal Read/Write
operation; default)
1 = Reduced power down enabled
18
Datasheet