KS8993F-EVAL Micrel Inc, KS8993F-EVAL Datasheet - Page 35

• Manufacturer Part Number: KS8993F-EVAL
• Description: EVAL KIT EXPERIMENTAL KS8993F
• Manufacturer: Micrel Inc

Specifications of KS8993F-EVAL

• Lead Free Status / RoHS Status: Not applicable / Not applicable

The MII (Media Independent Interface) is specified by the IEEE 802.3 committee and provides a common interface
between physical layer and MAC layer devices. The MII Interface provided by the KS8993F is connected to the
device’s third MAC. The interface contains two distinct groups of signals: one for transmission and the other for
reception. The following table describes the signals used in the MII interface.
The MII interface operates in either PHY mode or MAC mode. The interface is a nibble wide data interface, and
therefore runs at ¼ the network bit rate (not encoded). Additional signals on the transmit side indicate when data is
valid or when an error occurs during transmission. Likewise, the receive side has indicators that convey when the
data is valid and without physical layer errors. For half duplex operation, there is a signal that indicates a collision has
occurred during transmission.
Note that the signal MRXER is not provided on the interface for PHY mode operation and the signal MTXER is not
provided on the interface for MAC mode operation. Normally, MRXER would indicate a receive error coming from the
physical layer device.
appropriate for this configuration. For PHY mode operation, if the device interfacing with the KS8993F has an MRXER
pin, it should be tied low. For MAC mode operation, if the device interfacing with the KS8993F has an MTXER pin, it
should be tied low.
2.6
The SNI (Serial Network Interface) or 7-wire is compatible with some controllers used for network layer protocol
processing. In SNI mode, the KS8993F acts like a PHY and the external controller functions as the MAC. The
KS8993F can interface directly with external controllers using the 7-wire interface. These signals are divided into two
groups, one for transmission and the other for reception. The signals involved are described in the following table.
Micrel, Inc.
May 2006
SNI (7-wire) Interface Operation
KS8993F PHY mode connections
External MAC
signals
MTXEN
MTXER
MTXD3
MTXD2
MTXD1
MTXD0
MTXC
MCOL
MCRS
MRXDV
MRXER
MRXD3
MRXD2
MRXD1
MRXD0
MRXC
Pin Description
MTXER would indicate a transmit error from the MAC device.
KS8993F PHY
signals
SMTXEN
SMTXER
SMTXD[3]
SMTXD[2]
SMTXD[1]
SMTXD[0]
SMTXC
SCOL
SCRS
SMRXDV
(not used)
SMRXD[3]
SMRXD[2]
SMRXD[1]
SMRXD[0]
SMRXC
Table 4: SNI (7-wire) Signals
Pin Description
Transmit enable
Transmit error
Transmit data bit 3
Transmit data bit 2
Transmit data bit 1
Transmit data bit 0
Transmit clock
Collision detection
Carrier sense
Receive data valid
Receive error
Receive data bit 3
Receive data bit 2
Receive data bit 1
Receive data bit 0
Receive clock
SNI signals
Table 3: MII Signals
35
KS8993F signals
KS8993F MAC mode connections
External PHY
signals
MTXEN
MTXER
MTXD3
MTXD2
MTXD1
MTXD0
MTXC
MCOL
MCRS
MRXDV
MRXER
MRXD3
MRXD2
MRXD1
MRXD0
MRXC
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KS8993F MAC
signals
SMRXDV
(not used)
SMRXD[3]
SMRXD[2]
SMRXD[1]
SMRXD[0]
SMRXC
SCOL
SCRS
SMTXEN
SMTXER
SMTXD[3]
SMTXD[2]
SMTXD[1]
SMTXD[0]
SMTXC
These signals are not
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M9999-052206
KS8993F/FL