Intel PCI-X, Intel Gigabit Ethernet Controllers manual Software Developer’s Manual 139

Power Management

6.3.3.4Power Management Control / Status Register - (PMCSR) 2 Bytes Offset = 4 (RO)

Bits	Default	R/W	Description
			PME_Status – This bit is set when the function would normally assert the
			PME# signal independent of the state of the PME_En bit. The Ethernet
		Read/	controller returns a value of 1b for this bit if a Wakeup condition has been
	0b (see		detected.
15		Write 1b	Writing a 1b clears this bit and deasserts PME#a.
	description)
		to clear	If the AUX_POWER input is 1b, the PME_Status field is only reset by
			LAN_PWR_GOOD. If AUX_POWER is 0b, PME_Status is also reset on the
			deassertion (rising edge) of RST#.
	00b		Data_Scale - This 2- bit read-only field indicates the scaling factor to be
	01b if	Read	used when interpreting the value of the Data register. This field outputs 01b
14:13	Manageability is		(to indicate units of 0.1 watt) when Manageability is enabled in the
		Only
	enabled		EEPROM and the Data_Select field is set to 0, 3, 4, or 7, and 00b
	(see description)		otherwise.
		Read/	Data_Select - This 4-bit field is used to select which data is to be reported
12:09	0000b		through the Data register and Data_Scale field. These bits are only writable
		Write
			when Power Management is enabled via EEPROM.
			PME_En – If Power Management is not disabled in the EEPROM, writing a
			1b to this register enables Wakeup and causes the Ethernet controller to
			assert PME# when it receives a Wakeup event enabled in the Wakeup Filter
			Control Register (WUFC).
			Note: This bit cannot be set for the 82541ER.
08	0b on Power-On	Read/	If Power Management is disabled in the EEPROM, writing a 1b to this bit
	reset	Write	has no affect, and does not set the bit to 1b.
			If the AUX_POWER input is 1b, the PME_En field is only reset by
			LAN_PWR_GOOD. If AUX_POWER is 0b, it is also reset on the
			deassertion (rising edge) of RST#.
			Note: If APM Wakeup is enabled, the PME# pin can be asserted even if
			PME_En is 0b. See Section 6.4.1 for details.
07:02	000000b	Read	Reserved - The Ethernet controller returns a value of 000000b for this field.
		Only
			PowerState - This 2-bit field is used both to determine the current power
			state of a function and to set the function into a new power state. The
			definition of the field values is as follows:
			00b - D0
			01b - D1 (ignored if written with this value)
01:00	00b	Read/	10b - D2 (ignored if written with this value)
			11b - D3
		Write
			If software attempts to write an unsupported state to this field, 00b or 10b, or
			if Power Management is disabled in the EEPROM, then the Ethernet
			controller completes the write operation normally on the bus, however the
			data is discarded and no state change occurs.
			These bits are cleared and the power state is returned to D0 after the trailing
			edge of RST#.

a.Not applicable to the 82541ER.

This register is used to control and monitor power management events in the Ethernet controller. If auxiliary power is present, as indicated by AUX_POWER = 1b, a PCI reset does not clear PME_En and PME_Status.

Software Developer’s Manual 139