IP178G datasheet(21/76 Pages) ETC2

21 / 76 page

IP178G

Data Sheet

21 / 76

December 19, 2012

IP178G-DS-R01.3

4.3

Green Power

IP178G provides various power management modes to save the power consumption. In addition to

the power down mode defined on IEEE802.3, two extra power saving modes are used to further reduce

the system power consumption.

4.3.1

Auto Power Saving Mode

IP178G will automatically enter this mode if no cable link is established. After entering this mode,

IP178G will shutdown unnecessary function and issue the link pulse at a rate lower than the regular rate

specified on IEEE 802.3.

4.3.2

IEEE802.3az EEE (Energy Efficient Ethernet)

In order to enter this mode, the PHY part should declare the EEE capability during the

auto-negotiation phase.

It’s the higher layer’s responsibility to memorize the link partner’s wakeup time and wakeup the link

partner before sending data. The higher layer means a mechanism that can evaluate the packet buffer

utilization and wake the link partner before sending the data. In general speaking, this mechanism

probably consists of at least one of the following items: the packet buffer manager, the application

program and OS.

The EEE module works well at LPI (Low Power Idle) mode when

1. Link at full-duplex and

2. Auto-negotiation is enabled in both local and remote PHYs and

3. 100Mbps full duplex and

4. EEE ability is supported in both local & remote PHYs and

5. EEE_EN (Reg 22.0[7:0]) is enabled for EEE function via default value and

6. SLEEP_TIMER (Reg 22.1[11:0]) is the default value for EEE sleep timer and

7. WAKE_TIME (Reg 22.2~9) is the default value for EEE wake time.

4.3.3

WOL+ (Wake On LAN Plus)

IP178G not only consumes low power, but also provides various energy-saving methods to save the

power. These combined methods make IP178G a “green” PHY. The following pictures show the method.

Figure 2

WOL+ Application Diagram

Packet wakes it up

No-Traffic leads it to sleep

IP178G

IP178G Datenblatt(PDF) 21 Page - List of Unclassifed Manufacturers