6.0 Power Management and Wake-On-LAN
(Continued)
89
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DP83816
6.5.2 Wake Events
If the device detects a wake event while in WOL mode, it
will assert the PMEN pin low to signal the system that a
wake event has occurred. The system should then bring
the device out of WOL mode as described below.
6.5.3 Exiting WOL Mode
The following steps are required to bring the device out of
WOL mode (with or without an accompanying wake event):
1.
If the Power Management state is D3cold, the system
will assert PCI reset, restore PCI bus power, and
restart the PCI clock. This will also return the Power
State to D0. The PCI configuration registers (i.e. base
addresses, bus master enable, etc.) must be reinitial-
ized.
2.
Write a 0 to Power State bits [0:1] in the PMCSR (in
case the WOL Power State was not D3hot or D3cold)
and PME Enable. These can be done in one opera-
tion, or Power State can be written first. Turning off
PME Enable will cause the device to de-assert the
PMEN pin, if it was asserted.
3.
If the WOL Power State was D3hot or D3cold, reinitial-
ize the PCI configuration registers (i.e. base
addresses, bus master enable, etc.). An ACPI-com-
patible operating system should handle this step. Note
that operational registers will not be accessible until
this step is completed.
4.
If a wake event occurred, read the WCSR to deter-
mine what the event was.
5.
Write a 1 to PME Status. This will clear any wake
event in the device. An ACPI-compatible operating
system will perform this write to the PMCSR; a driver
can perform this write using the Clockrun Control/Sta-
tus Register (CCSR).
6.
If the wake event was a PHY interrupt from an internal
PHY, clear the event in the PHY registers. Refer to the
MISR in Section 4.3.11.
7.
Clear all bits in WCSR.
8.
Disable the receiver by writing a 1 to the Receiver Dis-
able bit in the Command Register (CR:RXD).
9.
Reconfigure RFCR as appropriate for normal opera-
tion.
10. Write a valid receive descriptor pointer to the Receive
Descriptor Pointer Register (RXDP)
11. Enable the receiver by writing a 1 to the Receiver
Enable bit in the Command Register (CR:RXE). If the
wake event was a packet, this will now be emptied
from the receive FIFO via DMA.
6.6 Sleep Mode
Sleep Mode is a system-level function that allows a device
to be placed in a lower power mode than WOL mode. In
sleep mode, the device will not be able to detect wake
events or signal the system that it needs service.
6.6.1 Entering Sleep Mode
The following steps are required to enter Sleep Mode:
1.
Disable the receiver by writing a 1 to the Receiver Dis-
able bit in the Command Register (CR:RXD).
2.
Write 0 to the Receive Descriptor Pointer Register
(RXDP)
3.
Force the receiver to reread the descriptor pointer by
writing a 1 to the Receiver Enable bit in the Command
Register (CR:RXE).
4.
Do not configure any wake events in WCSR.
5.
Write a 0 to PME Enable, and set the desired Power
State in PMCSR. These can be done in one operation.
An ACPI-compatible operating system should handle
this step.
6.
If the Power Management state is D3cold, the system
will assert PCI reset, stop the PCI clock, and remove
power from the PCI bus.
6.6.2 Exiting Sleep Mode
The following steps are required to bring the DP83816 out
of Sleep Mode:
1.
If the Power Management state is D3cold, the system
will assert PCI reset, restore PCI bus power, and
restart the PCI clock. This will also return the Power
State to D0. The PCI configuration registers (i.e. base
addresses, bus master enable, etc.) must be reinitial-
ized.
2.
Write a 0 to Power State bits [0:1] in the PMCSR (in
case the sleep Power State was not D3hot or D3cold).
3.
If the sleep Power State was D3hot or D3cold, reinitial-
izeaddresses, bus master enable, etc.). An ACPI-com-
patible operating system should handle this step. Note
that operational registers will not be accessible until
this step is completed.
4.
Disable the receiver by writing a 1 to the Receiver Dis-
able bit in the Command Register (CR:RXD).
5.
Write a valid receive descriptor pointer to the Receive
Descriptor Pointer Register (RXDP)
6.
Enable the receiver by writing a 1 to the Receiver
Enable bit in the Command Register (CR:RXE).
6.7 Pin Configuration for Power Management
Refer to Table 6-2 for proper pin connection for power
management configuration:
Note: *Refer to Demo Board schematics for additional information.
Table 6-2 PM Pin Configuration
Pin Name Pin No. Power Mgt No Power Mgt
PMEN
59
*PME#
3.3V
3VAUX
122
*3.3Vaux
GND
Summary of Contents for MacPHYTER-II DP83816
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