Specifications

Micrel, Inc.
KSZ8895MQ/RQ/FMQ
SW5-RMII MAC to MAC Connection
(‘PHY mode’)
SW5-RMII MAC to PHY Connection
(‘MAC mode’)
External
MAC
KSZ8895RQ
SW5-RMII
KSZ8895RQ
SW Signal
Type
Description
External
PHY
KSZ8895RQ
SW5-RMII
KSZ8895RQ SW
Signal Type
REF_CLK SMRXC
Output (clock
mode with
50MHz)
(Normal mode
without
connection)
Reference Clock --------
SMTXC/SM
REFCLK
Input (clock comes
from SMRXC in
clock mode or
external clock in
normal mode)
CRS_DV
SMRXDV
/SMCRSDV
Output
Carier sense/Receive
data valid
CRS_DV SMTXEN Input
RXD[1:0] SMRXD[1:0] Output Receive data bit [1:0] RXD[1:0] SMTXD[1:0] Input
TX_EN SMTXEN Input Transmit data enable TX_EN
SMRXDV
/SMCRSDV
Output
TXD[1:0] SMTXD[1:0] Input
Transmit data bit
[1:0]
TXD[1:0] SMRXD[1:0] Output
(not used) (not used) Receive error (not used) (not used)
---
SMTXC/SM
REFCLK
Input (clock
comes from
SMRXC in clock
mode or external
clock in normal
mode)
Reference Clock REF_CLK SMRXC
Output (clock mode
with 50MHz)
(Normal mode
without connection)
Note:
1. MAC/PHY mode in RMII is difference with MAC/PHY mode in MII, there is no strap pin and register configuration request in RMII, just follow
the signals connection in the table.
Table 5. Port 5 MAC5 SW5-RMII Connection
SNI Interface Operation
The serial network interface (SNI) is compatible with some controllers used for network layer protocol processing.
This interface can be directly connected to these types of devices. The signals are divided into two groups, one for
transmission and the other for reception. The signals involved are described in Table below.
SNI Signal Description KSZ8895MQ/RQ/FMQ Signal
TXEN Transmit Enable SMTXEN
TXD Serial Transmit Data SMTXD[0]
TXC Transmit Clock SMTXC
COL Collision Detection SCOL
CRS Carrier Sense SMRXDV
RXD Serial Receive Data SMRXD[0]
RXC Receive Clock SMRXC
Table 6. SNI Signals
This interface is a bit-wide data interface, so it runs at the network bit rate (not encoded). An additional signal on the
transmit side indicates when data is valid. Likewise, the receive side has an indicator that shows when the data is
valid.
For half-duplex operation there is a signal that indicates a collision has occurred during transmission.
March 12, 2014
41
Revision 1.7