KSZ9021GN TR Micrel Inc, KSZ9021GN TR Datasheet - Page 28

• Manufacturer Part Number: KSZ9021GN TR
• Description: Specifications: Number of Drivers/Receivers: 8/8 ; Type: Transceiver ; Voltage - Supply: 3.135 V ~ 3.465 V ; Package / Case: 64-VFQFN Exposed Pad ; Packaging: Tape & Reel (TR) ; Protocol: Gigabit Ethernet ; Lead Free Status: Lead Free ; RoHS Stat
• Manufacturer: Micrel Inc

Micrel, Inc.
KSZ9021GN
Power Management
The KSZ9021GN offers the following power management modes:
Power Saving Mode
This mode is a KSZ9021GN green feature to reduce power consumption when the cable is unplugged. It is in effect
when auto-negotiation mode is enabled and the cable is disconnected (no link).
Software Power-Down Mode
This mode is used to power down the KSZ9021GN device when it is not in use after power-up. Power-down mode is
enabled by writing a one to register 0h bit 11. In the power-down state, the KSZ9021GN disables all internal functions,
except for the MII management interface. The KSZ9021GN exits power-down mode after writing a zero to register 0h bit
11.
Chip Power-Down Mode
This mode provides the lowest power state for the KSZ9021GN when it is not in use and is mounted on the board. Chip
power-down mode is enabled at power-up / reset with the MODE[3:0] strap-in pins set to 0111. The KSZ9021GN exits
chip power down mode when a hardware reset is applied to RESET_N (pin 56) with the MODE[3:0] strap-in pins set to
an operating mode other than chip power-down mode.
September 2010
28
M9999-091010-1.1