Specifications

Micrel, Inc.
KSZ8895MQ/RQ/FMQ
MIIM Registers
All the registers defined in this section can be also accessed via the SPI interface. Note: different mapping
mechanisms are used for MIIM and SPI. The “PHYAD” defined in IEEE is assigned as “0x1” for Port 1, “0x2” for Port
2, “0x3” for Port 3, “0x4” for Port 4, and “0x5” for Port 5. The “REGAD” supported are 0x0-0x5 (0h-5h), 0x1D (1dh)
and 0x1F (1fh).
Address Name Description Mode Default
Register 0h: MII Control
15 Soft Reset
1, PHY soft reset.
0, Normal operation.
R/W
(SC)
0
14 Loop Back
1, Perform MAC loopback, loop back path as follows:
Assume the loop-back is at Port 1 MAC, Port 2 is the
monitor port.
Port 1 MAC Loopback (Port 1 reg. 0, bit 14 = ‘1’)
Start: RXP2/RXM2 (Port 2). Can also start from
port 3, 4, 5
Loopback: MAC/PHY interface of Port 1’s MAC
End: TXP2/TXM2 (Port 2). Can also end at
Ports 3, 4, 5 respectively
Setting address ox3,4,5 reg. 0, bit 14 = ‘1’ will
perform MAC loopback on Ports 3, 4, 5 respectively.
0, Normal Operation.
R/W 0
13 Force 100
1, 100Mbps.
0, 10Mbps.
R/W 1
12 AN Enable
1, Auto-negotiation enabled.
0, Auto-negotiation disabled.
R/W 1
11 Power Down
1, Power down.
0, Normal operation.
R/W 0
10 PHY Isolate
1, Electrical PHY isolation of PHY from Tx+/Tx-.
0, Normal operation.
R/W 0
9 Restart AN
1, Restart Auto-negotiation.
0, Normal operation.
R/W 0
8 Force Full Duplex
1, Full duplex.
0, Half duplex.
R/W 0
7 Collision Test Not supported. RO 0
6 Reserved RO 0
5 Hp_mdix
1 = HP Auto MDI/MDI-X mode
0 = Micrel Auto MDI/MDI-X mode
R/W 1
4 Force MDI
1, Force to MDI when disable auto MDI/MDI-X.
0, Force to MDI-X when disable auto MDI/MDI-X.
R/W 0
3 Disable Auto MDI/MDI-X
1, Disable auto MDI/MDI-X.
0, Enable auto MDI/MDI-X.
R/W 0
2 Disable far End fault
1, Disable far end fault detection.
0, Normal operation.
R/W 0
1 Disable Transmit
1, Disable transmit.
0, Normal operation.
R/W 0
0 Disable LED
1, Disable LED.
0, Normal operation.
R/W 0
March 12, 2014
100
Revision 1.7