DP83865-EB National Semiconductor, DP83865-EB Datasheet - Page 44

• 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

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3.0 Configuration
3.4 Auto-Negotiation Register Set
The strapping option settings of Auto-Negotiation, speed,
and duplex capabilities that initialized during power-up or at
reset can be altered any time by writing to the BMCR 0x00,
ANAR 0x04 or, to 1KTCR 0x09.
When Auto-Negotiation is enabled, the DP83865 transmits
the abilities programmed in the ANAR 0x04, and 1KTCR
0x09 via FLP Bursts. The following combinations of
10 Mbps,100 Mbps, 1000 Mbps, Half Duplex, and Full
Duplex modes may be selected.
The Auto-Negotiation protocol compares the contents of
the ANLPAR (received from link partner) and ANAR regis-
ters (for 10/100 Mbps operation) and the contents of
1000BASE-T status and control registers, and uses the
results to automatically configure to the highest perfor-
mance protocol (i.e., the highest common denominator)
between the local and the link partner. The results of Auto-
Negotiation may be accessed in registers BMCR 0x00
(Duplex Status and Speed Status), and BMSR 0x01 (Auto-
Neg Complete, Remote Fault, Link).
The BMCR 0x00 provides control for enabling, disabling,
and restarting the Auto-Negotiation process.
The BMSR 0x01 indicates the set of available abilities for
technology types, Auto-Negotiation ability, and extended
register capability. These bits are permanently set to indi-
cate the full functionality of the DP83865. The BMSR also
provides status on:
— Auto-Negotiation is completed on bit 5
— The Link Partner is advertising that a remote fault has
— A valid link has been established on bit 2
The ANAR 0x04 stores the capabilities advertised during
Auto-Negotiation. All available capabilities are transmitted
by default. However, the advertised capability can be sup-
pressed by writing to the ANAR. This is a commonly used
by a management agent to change (i.e., to force) the com-
munication technology.
The ANLPAR 0x05 is used to store the received base link
code word as well as all next page code words during the
negotiation that is transmitted from the link partner.
If Next Page is NOT being used, then the ANLPAR will
store the base link code word (link partner's abilities) and
retain this information from the time the page is received,
indicated by a ‘1’ in bit 1 of the ANER 0x06, through the
end of the negotiation and beyond.
Table 38. Advertised Modes during Auto-Negotiation,
SPEED1
occurred on bit 4
1
1
0
0
1
1
0
0
SPEED0
1
0
1
0
1
0
1
0
DUPLEX
0
0
0
0
1
1
1
1
AN_EN = 1
(Continued)
1000BASE-T HD, 100BASE-TX HD,
1000BASE-T HD, 100BASE-TX HD
1000BASE-T FD, 100BASE-TX FD,
1000BASE-T FD, 100BASE-TX FD
1000BASE-T HD, 10BASE-T HD
1000BASE-T FD, 10BASE-T FD
Adertised Modes
1000BASE-T HD
1000BASE-T FD
10BASE-T HD
10BASE-T FD
44
During the next page exchange operation, the station man-
ager can not wait till the end of Auto-Negotiation to read
the ANLPAR because the register is used to store both the
base and next pages. The next page content overwrites the
base page content. The station manager needs to closely
monitor the negotiation status and to perform the following
tasks.
— ANER 0x06 bit 1 is ‘1’ indicates a page is received. Sta-
— After reading the base page information, software needs
— The operation can be implemented as polled or interrupt
The ANER 0x06 indicates additional Auto-Negotiation sta-
tus. The ANER provides status on:
— A Parallel Detect Fault has occurred (bit 4, ANER 0x06).
— The Link Partner supports the Next Page function (bit 3,
— The DP83865 supports the Next Page function (bit 2,
— The current page being exchanged by Auto-Negotiation
— The Link Partner supports Auto-Negotiation (bit 0, ANER
The ANNPTR 0x07 contains the next page code word to be
transmitted. See also Section “2.3 Register Description”
for details.
3.5 Auto-MDIX resolution
The GigPHYTER V can determine if a “straight” or “cross-
over” cable is used to connect to the link partner. It can
automatically re-assign channel A and B to establish link
with the link partner, (and channel C and D in 1000BASE-T
mode). Auto-MDIX resolution precedes the actual Auto-
Negotiation process that involves exchange of FLPs to
advertise capabilities. Automatic MDI/MDIX is described in
IEEE 802.3ab Clause 40, section 40.8.2. It is not a required
implementation for 10BASE-T and 100BASE-TX.
Contact
tion manage reads the base page information from
ANLPAR0x05 and stores the content in the memory.
to write to ANNPTR 0x07 to load the next page informa-
tion to be sent.
driven. If another page is received by polling bit 1 in the
ANER 0x06 or by interrupt, the station manager reads bit
15 of the ANLPAR indicating the partner has more next
pages to send. If the partner has more pages to send,
ANNPTR needs to be written to load another next page.
ANER 0x06).
ANER 0x06).
has been received (bit1, ANER 0x06).
0x06).
Table 39. PMA signal to MDI and MDIX pin-out
1
2
3
4
5
6
7
8
MDI_A+
MDI_B+
MDI_C+
MDI_D+
MDI_A-
MDI_C-
MDI_B-
MDI_D-
MDI
MDI_D+
MDI_C+
MDI_B+
MDI_A+
MDI_D-
MDI_C-
MDI_B-
MDI_A-
MDIX