KSZ8893FQL datasheet(31/109 Pages) MICROCHIP

31 / 109 page

KSZ8893FQL

DS00003038A-page 30

 2019 Microchip Technology Inc.

3.3.8

MII INTERFACE OPERATION

The Media Independent Interface (MII) is specified in Clause 22 of the IEEE 802.3u Standard. It provides a common

interface between physical layer and MAC layer devices. The MII provided by the KSZ8893FQL is connected to device’s

third MAC. The interface contains two distinct groups of signals: one for transmission and the other for reception.

Table 3-9 describes the signals used by the MII bus.

TABLE 3-9:

MII SIGNALS

PHY Mode Connections

Pin Description

MAC Mode Connections

External MAC

Controller Signals

KSZ8893FQL

PHY Signals

External PHY

Signals

KSZ8893FQL

MAC Signals

MTXEN

SMTXEN

Transmit Enable

MTXEN

SMRXDV

MTXER

SMTXER

Transmit Error

MTXER

(NOT USED)

MTXD3

SMTXD[3]

Transmit Data Bit 3

MTXD3

SMRXD[3]

MTXD2

SMTXD[2]

Transmit Data Bit 2

MTXD2

SMRXD[2]

MTXD1

SMTXD[1]

Transmit Data Bit 1

MTXD1

SMRXD[1]

MTXD0

SMTXD[0]

Transmit Data Bit 0

MTXD0

SMRXD[0]

MTXC

SMTXC

Transmit Clock

MTXC

SMRXC

MCOL

SCOL

Collision Detection

MCOL

SCOL

MCRS

SCRS

Carrier Sense

MCRS

SCRS

MRXDV

SMRXDV

Receive Data Valid

MRXDV

SMTXEN

MRXER

(NOT USED)

Receive Error

MRXER

SMTXER

MRXD3

SMRXD[3]

Receive Data Bit 3

MRXD3

SMTXD[3]

MRXD2

SMRXD[2]

Receive Data Bit 2

MRXD2

SMTXD[2]

MRXD1

SMRXD[1]

Receive Data Bit 1

MRXD1

SMTXD[1]

MRXD0

SMRXD[0]

Receive Data Bit 0

MRXD0

SMTXD[0]

MRXC

SMRXC

Receive Clock

MRXC

SMTXC

The MII operates in either PHY mode or MAC mode. The data interface is a nibble wide and runs at one-quarter the

network bit rate (not encoded). Additional signals on the transmit side indicate when data is valid or when an error has

occurred during transmission. Similarly, the receive side has signals that convey when the data is valid and without phys-

ical layer errors. For half-duplex operation, the SCOL signal indicates if a collision has occurred during transmission.

The KSZ8893FQL does not provide the MRXER signal for PHY mode operation and the MTXER signal for MAC mode

operation. Normally, MRXER indicates a receive error coming from the physical layer device and MTXER indicates a

transmit error from the MAC device. Because the switch filters error frames, these MII error signals are not used by the

KSZ8893FQL. So, for PHY mode operation, if the device interfacing with the KSZ8893FQL has an MRXER input pin, it

needs to be tied low. And, for MAC mode operation, if the device interfacing with the KSZ8893FQL has an MTXER input

pin, it also needs to be tied low.

3.3.9

RMII INTERFACE OPERATION

The Reduced Media Independent Interface (RMII) specifies a low pin count Media Independent Interface (MII). RMII

provides a common interface between physical layer and MAC layer devices, and has the following key characteristics:

• Supports 10 Mbps and 100 Mbps data rates.

• Uses a single 50 MHz clock reference (provided externally).

• Provides independent 2-bit wide (di-bit) transmit and receive data paths.

• Contains two distinct groups of signals: one for transmission and the other for reception

The RMII provided by the KSZ8893FQL is connected to the device’s third MAC. It complies with the RMII Specification.

The following table describes the signals used by the RMII bus. Refer to RMII Specification for full detail on the signal

description.

KSZ8893FQL датащи(PDF) 31 Page - Microchip Technology

KSZ8893FQL датащи(HTML) 31 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 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL