Datasheet
KSZ8895MQX/RQX/FQX/MLX
DS00002246A-page 48 2016 Microchip Technology Inc.
3
Enable PHY
MII/RMII
1, enable PHY P5-MII/RMII interface (default).
Note: if not enabled, the switch will be tri-state all
outputs.
R/W
1
Pin LED[5][1] strap
option.
PD(0): isolate. PU(1):
Enable.
Note: LED[5][1]
has internal pull-up
(PU).
2 Reserved N/A Do not change. RO 1
1 UNH Mode
1, the switch will drop packets with 0x8808 in T/L
field, or DA=01-80-C2-00-00-01.
0, the switch will drop packets qualified as “flow
control” packets.
R/W 0
0
Link Change
Age
1, link change from “link” to “no link” will cause fast
aging (<800 µs) to age address table faster. After
an age cycle is complete, the age logic will return to
normal (300 ± 75 seconds). Note: If any port is
unplugged, all addresses will be automatically
aged out.
R/W 0
Register 3 (0x03): Global Control 1
7
Pass All
Frames
1, switch all packets including bad ones. Used
solely for debugging purpose. Works in conjunction
with sniffer mode.
R/W 0
6
2K Byte
packet
support
1 = enable support 2K Byte packet
0 = disable support 2K Byte packet
R/W 0
5
IEEE 802.3x
Transmit
Flow Control
Disable
0, will enable transmit flow control based on AN
result.
1, will not enable transmit flow control regardless of
AN result.
R/W
0
Pin PMRXD3
strap option.
PD(0): Enable Tx flow
control (default).
PU(1): Disable Tx/Rx
flow control.
Note: PMRXD3
has internal
pull-down.
4
IEEE 802.3x
Receive
Flow Control
Disable
0, will enable receive flow control based on AN
result.
1, will not enable receive flow control regardless of
AN result.
Note: Bit 5 and bit 4 default values are controlled
by the same pin, but they can be programmed
independently.
R/W
0
Pin PMRXD3 strap
option.
PD (0): Enable Rx
flow control (default).
PU(1): Disable Tx/Rx
flow control.
Note: PMRXD3
has internal
pull-down.
3
Frame
Length Field
Check
1, will check frame length field in the IEEE packets
If the actual length does not match, the packet will
be
dropped (for L/T <1500).
R/W 0
TABLE 4-2: GLOBAL REGISTER DESCRIPTIONS (CONTINUED)
Address Name Description Mode Default