lan7500 Standard Microsystems Corp., lan7500 Datasheet - Page 34

• Manufacturer Part Number: lan7500
• Description: Hi-speed Usb 2.0 To 10/100/1000 Ethernet Controller
• Manufacturer: Standard Microsystems Corp.

Revision 1.0 (11-01-10)
Chapter 5 NetDetach Operation
5.1
NetDetach
NetDetach is a mode of operation where the device detaches from the USB bus after the Ethernet
cable is disconnected. This is advantageous for mobile devices, as an attached USB device may
prevent the Host CPU from entering the ACPI C3 state. Allowing the CPU to enter the C3 state
maximizes battery life, as the C3 state is the lowest of the four APCI power states.
When detached, the device is in a low power state. After the Ethernet cable is reconnected, or a
programmed GPIO pin asserts, the device automatically attaches to the USB bus.
...ZZZ
LAN7500/
LAN7500i
SMSC
Ethernet
Figure 5.1 LAN7500/LAN7500i Detach
DATASHEET
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2
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Battery-powered Netbook PC
may enter C3 sleep mode
Remove Ethernet Cable
USB Electricals Detach
Hi-Speed USB 2.0 to 10/100/1000 Ethernet Controller
SMSC LAN7500/LAN7500i
Datasheet