Data Sheet

Interconnects—Ethernet Controller I210
121
Table 3-32 lists link speed as function of power management state, link speed control, and GbE speed
enabling:
The internal PHY initiates auto-negotiation without a direct driver command in the following cases:
• When the PHPM.Disable 1000 in non-D0a bit is set and 1000 Mb/s is disabled on D3 or Dr entry
(but not in D0a), the PHY auto-negotiates on entry.
• When the PHPM.Disable 100 in non-D0a is set and 1000 Mb/s and 100 Mb/s are disabled on D3 or
Dr entry (but not in D0a), the PHY auto-negotiates on entry.
• When PHPM.LPLU changes state with a change in a power management state. For example, on
transition from D0a without PHPM.LPLU to D3 with PHPM.LPLU. Or, on transition from D3 with
PHPM.LPLU to D0 without LPLU.
• On a transition from D0a state to a non-D0a state, or from a non-D0a state to D0a state, and
PHPM.LPLU is set.
Notes:
• The Low-Power Link-Up (LPLU) feature previously described should be disabled (in both
D0a state and non-D0a states) when the intended advertisement is anything other than
10 Mb/s only, 10/100 Mb/s only, or 10/100/1000 Mb/s. This is to avoid reaching (through
the LPLU procedure) a link speed that is not advertised by the user.
• When the LAN PCIe function is disabled via the LAN_PCI_DIS bit in the Software Defined
Pins Control Flash word, the relevant function is in a Non-D0a state. As a result,
management might operate with reduced link speed if the LPLU, Disable 1000 in Non-
D0a or Disable 100 in Non-D0a Flash bits are set and the MANC.Keep_PHY_Link_Up bit
(also known as “Veto bit”) is cleared.
• When the Keep_PHY_Link_Up bit (also known as veto bit) in the MANC register is set,
The PHY does not change its link speed as a result of a change in the device power state
(such as move to D3).
Table 3-32. Link Speed vs. Power State
Power
Management
State
Low
Power
Link Up
(PHPM.1,
PHPM.2)
GbE Disable Bits
100M Disable
Bit
PHY Speed Negotiation
Disable 1000
(PHPM.6)
Disable 1000
in non-D0a
(PHPM.3)
Disable 100
in non-D0a
(PHPM.9)
D0a
0, Xb
0b X X
PHY negotiates to highest speed advertised
(normal operation).
1b X X
PHY negotiates to highest speed advertised
(normal operation), excluding 1000 Mb/s.
1, Xb
0b X X
PHY goes through Low Power Link Up (LPLU)
procedure, starting with advertised values.
1b X X
PHY goes through LPLU procedure, starting with
advertised values. Does not advertise 1000 Mb/s.
Non-D0a
X, 0b
0b 0b 0b PHY negotiates to highest speed advertised.
0b 1b 0b
PHY negotiates to highest speed advertised,
excluding 1000 Mb/s.
1b X 0b
X X 1b PHY negotiates and advertises only 10 Mb/s
X, 1b
0b 0b 0b
PHY goes through LPLU procedure, starting at 10
Mb/s.
0b 1b 0b
PHY goes through LPLU procedure, starting at 10
Mb/s. Does not advertise 1000 Mb/s.
X X 1b PHY negotiates and advertises only 10 Mb/s