Field Name Bits Default Description
DSI 21 0b Read only.
The Device Specific Initialization bit indicates whether
special initialization of this function is required (beyond the
standard PCI configuration header) before the generic class
device driver is able to use it.
Aux_Current 24:22 000b Read only.
This 3 bit field reports the 3.3Vaux auxiliary current
requirements for the PCI function.
If the Data Register has been implemented by this function:
• Reads of this field must return a value of “000b”.
• The Data Register takes precedence over this field for
3.3Vaux current requirement reporting.
D1_Support 25 1b If this bit is a “1”, this function supports the D1
Power Management State.
D2_Support 26 1b If this bit is a “1”, this function supports the D2
Power Management State.
PME_Support 31:27 0Fh Read only.
This 5-bit field indicates the power states in which the
function may assert PME#. A value of 0b for any bit
indicates that the function is not capable of asserting the
PME# signal while in that power state.
bit(31) 1XXXXb - PME# can be asserted from D3cold bit(30)
X1XXXb - PME# can be asserted from D3hot
bit(29) XX1XXb - PME# can be asserted from D2
bit(28) XXX1Xb - PME# can be asserted from D1
bit(27) XXXX1b - PME# can be asserted from D0
Field Name Bits Default Description
PowerState 1:0 00b 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 given below.
00b - D0
01b - D1
10b - D2
11b - D3hot
If software attempts to write an unsupported, optional state to
this field, the write operation must be completed normally on
the bus; however, the data is discarded and no state change
occurs.
Reserved 7:2 Reserved
PME_En 8 0b A “1” enables the function to assert PME#. When “0”, PME#
assertion is disabled. This bit defaults to “0” if the function
does not support PME# generation from D3cold.
Data_Select 12:9 000 0b This 4-bit field is used to select which data is to be reported
through the Data register and Data_Scale field.
Data_Scale 14:13 00b This 2-bit read-only field indicates the scaling factor to be
used when interpreting the value of the Data register. The
value and meaning of this field will vary depending on which
data value has been selected by the Data_Select field.
PME_Status 15 0b This bit is set when the function would normally assert the
PME# signal independent of the state of the PME_En bit.
Reserved 21:16 Reserved