Datasheet
2016-2017 Microchip Technology Inc. DS00002117F-page 39
KSZ9031RNX
Note 4-1 RW = Read/Write; RO = Read Only; SC = Self-Cleared; LH = Latch High; LL = Latch Low.
D.4:0 MMD –
Device
Address
These five bits set the MMD device address. RW 0_0000
Register Eh - MMD Access – Register/Data
E.15:0 MMD –
Register/
Data
For the selected MMD device address (Reg. Dh,
Bits [4:0]),
When Reg. Dh, Bits [15:14] = 00, this register
contains the read/write register address for the
MMD device address.
Otherwise, this register contains the read/write
data value for the MMD device address and its
selected register address.
See also Reg. Dh, Bits [15:14], for descriptions of
post increment reads and writes of this register for
data operation.
RW 0000_0000_0000_00
00
Register Fh – Extended Status
F.15 1000BASE-X
Full-Duplex
1 = PHY can perform 1000BASE-X full-duplex
0 = PHY cannot perform 1000BASE-X full-duplex
RO 0
F.14 1000BASE-X
Half-Duplex
1 = PHY can perform 1000BASE-X half-duplex
0 = PHY cannot perform 1000BASE-X half-duplex
RO 0
F.13 1000BASE-T
Full-Duplex
1 = PHY can perform 1000BASE-T full-duplex
0 = PHY cannot perform 1000BASE-T full-duplex
RO 1
F.12 1000BASE-T
Half-Duplex
1 = PHY can perform 1000BASE-T half-duplex
0 = PHY cannot perform 1000BASE-T half-duplex
RO 1
F.11:0 Reserved Ignore when read RO —
TABLE 4-4: VENDOR-SPECIFIC REGISTER DESCRIPTIONS
Address Name Description
Mode
Note 4-1
Default
Register 11h – Remote Loopback
11.15:9 Reserved Reserved RW 0000_000
11.8 Remote
Loopback
1 = Enable remote loopback
0 = Disable remote loopback
RW 0
11.7:1 Reserved Reserved RW 1111_010
11.0 Reserved Reserved RO 0
Register 12h – LinkMD – Cable Diagnostic
12.15 Cable
Diagnostic
Test Enable
Write value:
1 = Enable cable diagnostic test. After test has
completed, this bit is self-cleared.
0 = Disable cable diagnostic test.
Read value:
1 = Cable diagnostic test is in progress.
0 = Indicates cable diagnostic test (if enabled) has
completed and the status information is valid for
read.
RW/SC 0
12.14 Reserved This bit should always be set to ‘0’. RW 0
TABLE 4-3: IEEE-DEFINED REGISTER DESCRIPTIONS (CONTINUED)
Address Name Description
Mode
Note 4-1
Default