DP83865-EB National Semiconductor, DP83865-EB Datasheet - Page 41

• Manufacturer Part Number: DP83865-EB
• Description: BOARD EVALUATION DP83865
• Manufacturer: National Semiconductor

Specifications of DP83865-EB

• Main Purpose: Interface, Ethernet
• Utilized Ic / Part: DP83865
• Lead Free Status / RoHS Status: Not applicable / Not applicable

3.0 Configuration
3.2.2 Master/Slave
In 1000BASE-T the two link partner devices have to be
configured, one as Master and the other as Slave. The
Master device by definition uses a local clock to transmit
data on the wire; the Slave device uses the clock recov-
ered of the incoming data from the link partner for transmit-
ting its data. The Master and Slave assignments can be
manually set by using strapping options or register writes.
When the AN_EN pin is strapped low, strapping MULTI_EN
pin low selects Slave and high selects Master mode. Reg-
ister 9 bits 12:11 allows software to overwrite the strapping
Master/Slave setting (Table 30). Note that if both the link
partner and the local device are manually given the same
Master/Slave assignment, an error will occur as indicated
in 1KSTSR 0x0A bit 15.
Depending on what the link partner is configured to, the
manual Master/Slave mode can be resolved to eight possi-
ble outcomes. Only two National PHYs will be able to link
to each other in manual configuration mode.
3.3 Auto-Negotiation
All 1000BASE-T PHYs are required to support Auto-Nego-
tiation. (The 10/100 Mbps Ethernet PHYs had an option to
support Auto-Negotiation, as well as parallel detecting
when a link partner did not support Auto-Neg.) The Auto-
Negotiation function in 1000BASE-T has three primary pur-
poses:
— Auto-Negotiation of Speed & Duplex Selection
— Auto-Negotiation of Master/Slave Resolution
— Auto-Negotiation of Pause/Asymetrical Pause Resolu-
DUPLEX SPEED[1] SPEED[0]
Table 30. 1000BASE-T Master/Slave Sel., AN_EN = 0
MULTI_EN
tion
0
0
0
0
1
1
1
1
Table 29. Speed/Duplex Selection, AN_EN = 0
0
1
Slave mode
Master mode
0
0
1
1
0
0
1
1
(Continued)
0
1
0
1
0
1
0
1
Manual Mode
10BASE-T HD
100BASE-TX HD
1000BASE-T HD
(Between National
PHYs only)
Reserved
10BASE-T FD
100BASE-TX FD
1000BASE-T FD
(Between National
PHYs only)
Reserved
Manual Mode
(
Table 32
)
41
.
The DP83865 also supports features such as:
— Next Page
— Parallel Detection for 10/100 Mbps
— Restart Auto-Negotiation through software
3.3.1 Speed/Duplex Selection - Priority Resolution
The Auto-Negotiation function provides a mechanism for
exchanging configuration information between the two
ends of a link segment. This mechanism is implemented by
exchanging Fast Link Pulses (FLP). FLP are burst pulses
that provide the signalling used to communicate the abili-
ties between two devices at each end of a link segment.
For further details regarding Auto-Negotiation, refer to
Clause 28 of the IEEE 802.3u specification. The DP83865
supports six different Ethernet protocols: 10BASE-T Full
Duplex, 10BASE-T Half Duplex, 100BASE-TX Full Duplex,
100BASE-TX Half Duplex, 1000BASE-T Full Duplex, and
1000BASE-T Half Duplex. The process of Auto-Negotiation
ensures that the highest performance protocol is selected
(i.e., priority resolution) based on the advertised abilities of
the Link Partner and the local device. (Table 33)
.
Advertise
Advertise
DP83865
DP83865
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Master
Master
Master
Master
Master
Master
Master
Master
Slave
Slave
Slave
Slave
Slave
Slave
Slave
Slave
Table 31. Master/Slave Resolution, AN_EN = 0
Table 32. Master/Slave Resolution, AN_EN = 0
Link Partner
Link Partner
Single-node
Single-node
Single-node
Single-node
Multi-node
(Auto-neg)
(Auto-neg)
Multi-node
(Auto-neg)
(Auto-neg)
Multi-node
(Auto-neg)
(Auto-neg)
Multi-node
(Auto-neg)
(Auto-neg)
Advertise
Advertise
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Master
Master
Master
Master
Slave
Slave
Slave
Slave
Unresolved
Unresolved
Unresolved
Unresolved
Outcome
Outcome
DP83865
DP83865
No Link
No Link
No Link
No Link
Master
Master
Master
Master
Master
Master
Slave
Slave
Slave
Slave
Slave
Slave
www.national.com
Link Partner
Link Partner
Unresolved
Unresolved
Unresolved
Unresolved
Outcome
Outcome
No Link
No Link
No Link
No Link
Master
Master
Master
Master
Master
Master
Slave
Slave
Slave
Slave
Slave
Slave