Filter
Top Products
188 Software Developer’s Manual
PHY Functionality and Features
11.1.2 Next Page Exchanges
If 1000BASE-T mode is advertised, then the Ethernet controller PHY automatically sends the
appropriate next pages to advertise the capability and negotiate master/slave mode of operation. If
a developer does not want to transmit additional next pages, the next page bit (PCI-Config Register
bit 15) can be set to 0b and the software need take no further action.
If next pages in addition to the ones required for 1000BASE-T are needed, then the software can
set Auto-Negotiation Expansion Register bit 15 to 1b, and send and receive additional next pages
via the Next Page Transmit Register (NPT) and Link Partner Next Page Register (LPN),
respectively. The PHY stores the previous results from the Link Partner Next Page Register (LPN)
in internal registers so that new next pages can overwrite the Link Partner Next Page Register
(LPN).
Note: 1000BASE-T next page exchanges are automatically handled without any software intervention,
regardless of whether or not additional next pages are sent.
11.1.3 Register Update
Changes to PHY Control Register bits 6, 8, 12, and 13, and PHY Specific Control Register bits 3,
4, 6:5, 9:8 and 11, do not take effect unless one of the following takes place (copper only):
• PHY soft reset (PHY Control Register bit 15)
• Restart Auto-Negotiation (PHY Control Register bit 9)
• Transition of PHY from IEEE power-down to normal operation (PHY Control Register bit 11)
• The link goes down
To enable or disable Auto-Negotiation, PHY Control Register bit 12 should be changed
simultaneously with either PHY Control Register bits 15 or 9. For example, to disable Auto-
Negotiation and force 10BASE-T half-duplex mode, the PHY Control Register should be written
with 8000h.
To disable Auto-Negotiation (fiber only), set TXCW.ANE = 0.
The Auto-Negotiation Expansion Register and the 1000BASE-T Control Register are internally
latched once every time the Auto-Negotiation enters the
Ability Detect state in the arbitration state
machine. As a result, a write to the Auto-Negotiation Expansion Register or the 1000BASE-T
Control Register has no effect once the PHY begins to transmit Fast Link Pulses (FLPs). This
guarantees that sequences of FLPs transmitted are consistent with one another.
The Next Page Transmit Register is treated similarly to the Auto-Negotiation Expansion Register
and the 1000BASE-T Control Register during additional next page exchanges.