KSZ9031RNXVC datasheet(27/78 Pages) MICROCHIP

27 / 78 page

 2016 Microchip Technology Inc.

DS00002117C-page 27

KSZ9031RNX

3.16

Power Management

The KSZ9031RNX incorporates a number of power-management modes and features that provide methods to consume

less energy. These are discussed in the following sections.

3.16.1

ENERGY-DETECT POWER-DOWN MODE

Energy-detect power-down (EDPD) mode is used to further reduce the transceiver power consumption when the cable

is unplugged. It is enabled by writing a one to MMD Address 1Ch, Register 23h, Bit [0], and is in effect when auto-nego-

tiation mode is enabled and the cable is disconnected (no link).

In EDPD Mode, the KSZ9031RNX shuts down all transceiver blocks, except for the transmitter and energy detect cir-

cuits. Power can be reduced further by extending the time interval between the transmissions of link pulses to check for

the presence of a link partner. The periodic transmission of link pulses is needed to ensure the KSZ9031RNX and its

link partner, when operating in the same low-power state and with Auto MDI/MDI-X disabled, can wake up when the

cable is connected between them. By default, EDPD mode is disabled after power-up.

3.16.2

SOFTWARE POWER-DOWN MODE

This mode is used to power down the KSZ9031RNX device when it is not in use after power-up. Software power-down

(SPD) mode is enabled by writing a one to Register 0h, Bit [11]. In the SPD state, the KSZ9031RNX disables all internal

functions, except for the MII management interface. The KSZ9031RNX exits the SPD state after a zero is written to Reg-

ister 0h, Bit [11].

3.16.3

CHIP POWER-DOWN MODE

This mode provides the lowest power state for the KSZ9031RNX device when it is mounted on the board but not in use.

Chip power-down (CPD) mode is enabled after power-up/reset with the MODE[3:0] strap-in pins set to ‘0111’. The

KSZ9031RNX exits CPD mode after a hardware reset is applied to the RESET_N pin (Pin 42) with the MODE[3:0] strap-

in pins set to an operating mode other than CPD.

3.17

Wake-On-LAN

Wake-On-LAN (WOL) is normally a MAC-based function to wake up a host system (for example, an Ethernet end

device, such as a PC) that is in standby power mode. Wake-up is triggered by receiving and detecting a special packet

(commonly referred to as the “magic packet”) that is sent by the remote link partner. The KSZ9031RNX can perform the

same WOL function if the MAC address of its associated MAC device is entered into the KSZ9031RNX PHY registers

for magic-packet detection. When the KSZ9031RNX detects the magic packet, it wakes up the host by driving its power

management event (PME) output pin low.

By default, the WOL function is disabled. It is enabled by setting the enabling bit and configuring the associated registers

for the selected PME wake-up detection method.

The KSZ9031RNX provides three methods to trigger a PME wake-up:

• Magic-packet detection

•Customized-packet detection

• Link status change detection

GTX_CLK

Input

TX_EN

Input

RX_DV

Input

RX_CLK

Input

INT_/PME_N2

Input

MDC

Input

MDIO

Input

CLK125_NDO

Output

TABLE 3-11:

NAND TREE TEST PIN ORDER FOR KSZ9031RNX (CONTINUED)

Description

KSZ9031RNXVC Datasheet(PDF) 27 Page - Microchip Technology

KSZ9031RNXVC Datasheet(HTML) 27 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78

Datasheet Download

Link URL