KSZ8893M Datasheet, PDF (65/116 Pages) Micrel Semiconductor – Integrated 3-Port 10/100 Managed Switch with PHYs

Micrel, Inc.
KSZ8893MQL/MBL
Register 5 (0x05): Global Control 3 (continued)
Bit
Name
R/W Description
3
Weighted
R/W 0 = always transmit higher priority packets first
Fair Queue
Enable
1 = Weighted Fair Queueing enabled. When all four
queues have packets waiting to transmit, the
bandwidth allocation is q3:q2:q1:q0 = 8:4:2:1.
If any queues are empty, the highest non-empty
queue gets one more weighting. For example, if q2 is
empty, q3:q2:q1:q0 becomes (8+1):0:2:1.
Default
0
2-1
Reserved
R/W Reserved
00
Do not change the default values.
0
Sniff Mode
R/W = 1, will do RX AND TX sniff (both source port and
0
Select
destination port need to match)
= 0, will do RX OR TX sniff (either source port or
destination port needs to match). This is the mode
used to implement RX only sniff.
Register 6 (0x06): Global Control 4
Bit
Name
R/W Description
7
Repeater
R/W =1, enable repeater mode
Mode
=0, disable repeater mode
Default
0
Note: For repeater mode, all ports need to be set to
100BASE-TX and half duplex mode. PHY ports need
to have auto-negotiation disabled.
6
Switch MII Half R/W = 1, enable MII interface half-duplex mode.
Duplex Mode
= 0, enable MII interface full-duplex mode.
Pin SMRXD2
strap option.
Pull-down(0):
Full-duplex
mode
Pull-up(1):
Half-duplex
mode
Note:
SMRXD2 has
internal pull-
down.
5
Switch MII
R/W = 1, enable full duplex flow control on Switch MII
Pin SMRXD3
Flow Control
interface.
strap option.
Enable
= 0, disable full duplex flow control on Switch MII
Pull-down(0):
interface.
Disable flow
control
Pull- up(1):
Enable flow
control
Note:
SMRXD3 has
internal pull-
down.
February 2010
65
M9999-021110-1.6