KSZ9031MNX View Datasheet(PDF) - Microsemi Corporation

Part Name

Description

Manufacturer

KSZ9031MNX

Gigabit Ethernet Transceiver with GMII/MII Support

Microsemi Corporation 

KSZ9031MNX

The KSZ9031MNX combines GMII mode with MII mode to form GMII/MII mode to support data transfer at 10/100/

1000 Mbps. After power-up or reset, the KSZ9031MNX is configured to GMII/MII mode if the MODE[3:0] strap-in pins

are set to ‘0001’. See the Strapping Options - KSZ9031MNX section.

The KSZ9031MNX has the option to output a 125 MHz reference clock on CLK125_NDO (Pin 55). This clock provides

a lower-cost reference clock alternative for GMII/MII MACs that require a 125 MHz crystal or oscillator. The 125 MHz

clock output is enabled after power-up or reset if the CLK125_EN strap-in pin is pulled high.

The KSZ9031MNX provides a dedicated transmit clock input pin (GTX_CLK, Pin 32) for GMII mode, which is sourced

by the MAC for 1000 Mbps speed.

3.9.1 GMII SIGNAL DEFINITION

Table 3-3 describes the GMII signals. Refer to Clause 35 of the IEEE 802.3 Specification for more detailed information.

TABLE 3-3: GMII SIGNAL DEFINITION

GMII Signal Name

(per spec)

GMII Signal Name

(per KSZ9031MNX)

Pin Type (with

respect to PHY)

Pin Type (with

respect to MAC)

Description

GTX_CLK

TX_EN

TXD[7:0]

TX_ER

RX_CLK

RX_DV

RXD[7:0]

RX_ER

CRS

COL

GTX_CLK

TX_EN

TXD[7:0]

TX_ER

RX_CLK

RX_DV

RXD[7:0]

RX_ER

CRS

COL

Input

Input

Input

Input

Output

Output

Output

Output

Output

Output

Output

Output

Output

Output

Input

Input

Input

Input

Input

Input

Transmit Reference Clock

(125 MHz for 1000 Mbps)

Transmit Enable

Transmit Data[7:0]

Transmit Error

Receive Reference Clock

(125 MHz for 1000 Mbps)

Receive Data Valid

Receive Data[7:0]

Receive Error

Carrier Sense

Collision Detected

3.9.2 GMII SIGNAL DIAGRAM

The KSZ9031MNX GMII pin connections to the MAC are shown in Figure 3-4.

FIGURE 3-4:

KSZ9031MNX GMII INTERFACE

KSZ9031MNX

GTX _CLK

TX _EN

TXD [7:0]

TX _ER

GMII

ETHERNET MAC

GTX _CLK

TX _EN

TXD [7:0]

TX _ER

RX_CLK

RX _DV

RXD[7:0]

RX _ER

CRS

COL

RX_CLK

RX _DV

RXD[7:0]

RX _ER

CRS

COL

 2016 Microchip Technology Inc.

DS00002096C-page 19

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