3.0 Functional Description (Continued)
Table III. Auto-Negotiation Mode Select
AN1
AN0
Action
Mode
(Pin 46) (Pin 95)
FORCED MODES
0
1
M
M
0
PAR (19h) Bit 10 = 0, Bit 6 = 1, Bit 7= 0
ANAR (04h) [8:5] = 021h
Auto-Negotiation Disabled with Only Half-Duplex
10BASE-T Forced (Note 2)
PAR (19h) Bit 10 = 0, Bit 6 = 1, Bit 7= 1
ANAR (04h) [8:5] = 041h
Auto-Negotiation disabled with Only Full-Duplex
10BASE-T Forced (Note 2)
M
M
C
PAR (19h)) Bit 10 = 0, Bit 6 = 0, Bit 7= 0
ANAR (04h) [8:5] = 081h
Auto-Negotiation disabled with Only Half-Duplex
100BASE-X Forced (Note 2)
1
PAR (19h) Bit 10 = 0, Bit 6 = 0, Bit 7 = 1
ANAR (04h) [8:5] = 101h
Auto-Negotiation disabled with Only Full-Duplex
100BASE-X Forced (Note 2)
M
PAR (19h) Bit 10 = 0, Bit 6 = 0, Bit 7 = 1
ANAR (04h) [8:5] = 181h
Auto-Negotiation disabled with Only Full-Duplex
100BASE-X Forced
(Default advertisement set to 100BASE-X Half-
Duplex and 100BASE-X Full-Duplex)
M
C
C
C
PAR (19h) Bit 10 = 0, Bit 6 = 0, Bit 7 = 1
ANAR (04h) [8:5] = 141h
Auto-Negotiation disabled with Only Full-Duplex
100BASE-X Forced
(Default advertisement set to 100BASE-X Full-
Duplex and 10BASE-T Full Duplex)
PAR (19h) Bit 10 = 0, Bit 6 = 0, Bit 7 = 0
ANAR (04h) [8:5] = 0A1h
Auto-Negotiation disabled with Only Half-Duplex
100BASE-X Forced
(Default advertisement set to 100BASE-X Half-
Duplex and 10BASE-T Half-Duplex)
ADVERTISED MODES
M
M
PAR (19h) Bit 10 = 1
Auto-Negotiation Enabled for All DP83840A
Possible Protocols (Note 2)
ANAR (04h) [8:5] = 1E1h
0
0
PAR (19h) Bit 10 = 1
Auto-Negotiation Enabled with Only Half-Duplex
10BASE-T Available
ANAR (04h) [8:5] = 021h
0
1
PAR (19h) Bit 10 = 1
Auto-Negotiation Enabled with Only Full-Duplex
10BASE-T Available
ANAR (04h) [8:5] = 041h
1
0
PAR (19h) Bit 10 = 1
Auto-Negotiation Enabled with Only Half-Duplex
100BASE-X Available
ANAR (04h) [8:5] = 081h
1
1
PAR (19h) Bit 10 = 1
Auto-Negotiation Enabled with Only Full-Duplex
100BASE-X Available
ANAR (04h) [8:5] = 101h
C
C
1
1
PAR (19h) Bit 10 = 1
Auto-Negotiation Enabled with 100BASE-X Full-
Duplex and 10BASE- T Full Duplex Available
ANAR (04h) [8:5] = 141h
0
PAR (19h) Bit 10 = 1
Auto-Negotiation Enabled with 100BASE-X Half-
Duplex and 10BASE-T Half Duplex Available
ANAR (04h) [8:5] = 0A1h
C
C
PAR (19h) Bit 10 = 1
Auto-Negotiation Enabled with 100BASE-X Full-
Duplex and 100BASE-X Half Duplex Available
ANAR (04h) [8:5] = 181h
0
PAR (19h) Bit 10 = 1
Auto-Negotiation Enabled with 10BASE-T Full-
Duplex and 10BASE-T Half Duplex Available
ANAR (04h) [8:5] = 061h
Note 1:“M” indicates logic mid level (Vcc/2), “1” indicates logic high level, “0” indicates logic low level
Note 2:Default advertisement on enable of Auto-Negotiation via the ANAR set to 100BASE-X Full-Duplex, 100BASE-X Half-Duplex, 10BASE-T Full-Duplex,
and 10BASE-T Half-Duplex)
Version A
National Semiconductor
37
TI [ TEXAS INSTRUMENTS ]
