LXT970ATC datasheet(24/74 Pages) INTEL

24 / 74 page

LXT970A — Dual-Speed Fast Ethernet Transceiver

Datasheet

2.2.3.3

Repeater Mode

The LXT970A MII normally operates in DTE Mode (19.13 = 0). An alternative operating mode is

available for repeater applications (19.13 = 1).

In Repeater Mode, the Carrier Sense (CRS) and Tri-state (TRSTE) signals request and grant bus

access. The TRSTE pin controls only the receive channel of the MII (RX_DV, RX_ER, RX_CLK,

and RXD).

As shown in Figure 7, a central Repeater State Machine (RSM) is required to perform arbitration

and determine which LXT970A drives the MII Data Interface. The RSM is responsible for

enforcing collisions, and ensuring packets are not transmitted to the port they were received from.

This is accomplished by supplying each LXT970A with individual TX_EN outputs. Although

repeater operation is half-duplex, the LXT970A operates the MII as a full-duplex interface in

Repeater Mode. CRS is generated only on receive and Collision (COL) is never generated.

Repeater Mode is normally used with Slave Clock Mode (XI = GND and TX_CLK is an input).

2.2.3.4

MII Management Interface

The LXT970A supports the IEEE 802.3 MII Management Interface also known as the

Management Data Input/Output (MDIO) Interface. This interface allows upper-layer devices to

monitor and control the state of the LXT970A. MDIO interface consists of a physical connection, a

specific protocol which runs across the connection, and an internal set of addressable registers. The

physical interface consists of a data line (MDIO) and clock line (MDC), a control line (MDDIS)

Figure 7. Repeater Block Diagram

Repeater

State Machine

(RSM)

CRS

TRSTE

TX_EN

CRS

TRSTE

TX_EN

CRS

TRSTE

TX_EN

CRS

TRSTE

TX_EN

Receive Channel (RXD)

Transmit Channel (TXD)

LXT970A

LXT970ATC датащи(PDF) 24 Page - Intel Corporation

LXT970ATC датащи(HTML) 24 Page - Intel Corporation

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

датащи скачать

ссылки URL