KSZ8893-MQL Micrel Semiconductor, Inc., KSZ8893-MQL Datasheet - Page 34

• Manufacturer Part Number: KSZ8893-MQL
• Description: Integrated 3-Port 10/100 Managed Switch with PHYs
• Manufacturer: Micrel Semiconductor, Inc.

The KSZ8893MQL filters error frames, and thus does not implement the RX_ER output signal. To detect error
frames from RMII PHY devices, the SMTXER input signal of the KSZ8893MQL is connected to the RXER output
signal of the RMII PHY device.
Collision detection is implemented in accordance with the RMII Specification.
In RMII mode, tie MII signals, SMTXD[3:2] and SMTXER, to ground if they are not used.
The KSZ8893MQL RMII can interface with RMII PHY and RMII MAC devices. The latter allows two KSZ8893MQL
devices to be connected back-to-back. The following table shows the KSZ8893MQL RMII pin connections with an
external RMII PHY and an external RMII MAC, such as another KSZ8893MQL device.
SNI (7-Wire) Operation
The serial network interface (SNI) or 7-wire is compatible with some controllers used for network layer protocol
processing. In SNI mode, the KSZ8893MQL acts like a PHY and the external controller functions as the MAC.
The KSZ8893MQL 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
November 2005
External
PHY Signals
REF_CLK
TX_EN
TXD1
TXD0
CRS_DV
RXD1
RXD0
RX_ER
KSZ8893MQL
PHY-MAC Connections
Pin Descriptions
Transmit enable
Serial transmit data
Transmit clock
Collision detection
Carrier sense
Serial receive data
Receive clock
KSZ8893MQL
MAC Signals
REFCLK
SMRXDV
SMRXD[1]
SMRXD[0]
SMTXEN
SMTXD[1]
SMTXD[0]
SMTXER
Table 5: RMII Signal Connections
Pin
Descriptions
Reference Clock
Carrier sense/
Receive data valid
Receive data bit 1
Receive data bit 0
Transmit enable
Transmit data bit 1
Transmit data bit 0
Receive error
Table 6. SNI Signals
External MAC
Controller Signals
TXEN
TXD
TXC
COL
CRS
RXD
RXC
34
KSZ8893MQL
MAC-MAC Connections
KSZ8893MQL
MAC Signals
REFCLK
SMRXDV
SMRXD[1]
SMRXD[0]
SMTXEN
SMTXD[1]
SMTXD[0]
(not used)
SCOL
SMRXDV
SMRXC
KSZ8893MQL
PHY Signals
SMTXEN
SMTXD[0]
SMTXC
SMRXD[0]
External
MAC Signals
REF_CLK
TX_EN
TXD1
TXD0
CRS_DV
RXD1
RXD0
(not used)
KSZ8893MQL/MQLI
M9999-111705