LM3S8971 Datasheet, PDF (444/577 Pages) List of Unclassifed Manufacturers – Microcontroller

Ethernet Controller
Register 20: Ethernet PHY Management Register 4 – Auto-Negotiation
Advertisement (MR4), address 0x04
This register provides the advertised abilities of the PHY used during Auto-Negotiation. Bits 8:5
represent the Technology Ability Field bits. This field can be overwritten by software to Auto-Negotiate
to an alternate common technology. Writing to this register has no effect until Auto-Negotiation is
re-initiated.
Ethernet PHY Management Register 4 – Auto-Negotiation Advertisement (MR4)
Base 0x4004.8000
Address 0x04
Type R/W, reset 0x01E1
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
NP reserved RF
reserved
A3
A2
A1
A0
S[4:0]
Type RO
RO
R/W
RO
RO
RO
RO
R/W
R/W
R/W
R/W
RO
RO
RO
RO
RO
Reset
0
0
0
0
0
0
0
1
1
1
1
0
0
0
0
1
Bit/Field
15
14
13
12:9
8
7
6
5
Name
NP
reserved
RF
reserved
A3
A2
A1
A0
Type
RO
RO
R/W
RO
R/W
R/W
R/W
R/W
Reset
0
0
0
0
1
1
1
1
Description
Next Page
When set, indicates the PHY is capable of Next Page exchanges to
provide more detailed information on the PHY’s capabilities.
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
Remote Fault
When set, indicates to the link partner that a Remote Fault condition
has been encountered.
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
Technology Ability Field[3]
When set, indicates that the PHY supports the 100Base-TX full-duplex
signaling protocol. If software wants to ensure that this mode is not used,
this bit can be written to 0 and Auto-Negotiation re-initiated with the
RANEG bit in the MR0 register.
Technology Ability Field[2]
When set, indicates that the PHY supports the 100Base-T half-duplex
signaling protocol. If software wants to ensure that this mode is not used,
this bit can be written to 0 and Auto-Negotiation re-initiated.
Technology Ability Field[1]
When set, indicates that the PHY supports the 10Base-T full-duplex
signaling protocol. If software wants to ensure that this mode is not used,
this bit can be written to 0 and Auto-Negotiation re-initiated.
Technology Ability Field[0]
When set, indicates that the PHY supports the 10Base-T half-duplex
signaling protocol. If software wants to ensure that this mode is not used,
this bit can be written to 0 and Auto-Negotiation re-initiated.
444
October 01, 2007
Preliminary