LPC Interface Bridge Registers (D31:F0)
Bit
Description
Power Button Override Status (PWRBTNOR_STS) — R/WC.
0 = Software clears this bit by writing a 1 to it.
1 = This bit is set any time a Power Button Override occurs (i.e., the power button is
pressed for at least 4 consecutive seconds), due to the corresponding bit in the
SMBus slave message, Intel ME Initiated Power Button Override, Intel ME
Initiated Host Reset with Power down or due to an internal thermal sensor
catastrophic condition. The power button override causes an unconditional
transition to the S5 state, as well as sets the AFTERG3_EN bit. The BIOS or SCI
handler clears this bit by writing a 1 to it. This bit is not affected by hard resets
via CF9h writes, and is not reset by RSMRST#. Thus, this bit is preserved
through power failures. Note that if this bit is still asserted when the global
SCI_EN is set then an SCI will be generated.
11
RTC Status (RTC_STS) — R/WC. This bit is not affected by hard resets caused by a
CF9 write, but is reset by RSMRST#.
0 = Software clears this bit by writing a 1 to it.
10
1 = Set by hardware when the RTC generates an alarm (assertion of the IRQ8#
signal). Additionally if the RTC_EN bit (PMBASE + 02h, bit 10) is set, the setting
of the RTC_STS bit will generate a wake event.
ME_STS — R/WC. This bit is set when the Intel Management Engine generates a
Non-Maskable wake event, and is not affected by any other enable bit. When this bit
is set, the Host Power Management logic wakes to S0.
9
This bit is only set by hardware and can only be reset by writing a one to this bit
position. This bit is not affected by hard resets caused by a CF9 write, but is reset by
RSMRST#.
Power Button Status (PWRBTN__STS) — R/WC. This bit is not affected by hard
resets caused by a CF9 write.
0 = If the PWRBTN# signal is held low for more than 4 seconds, the hardware clears
the PWRBTN_STS bit, sets the PWRBTNOR_STS bit, and the system transitions
to the S5 state with only PWRBTN# enabled as a wake event.
This bit can be cleared by software by writing a one to the bit position.
1 = This bit is set by hardware when the PWRBTN# signal is asserted Low,
independent of any other enable bit.
8
In the S0 state, while PWRBTN_EN and PWRBTN_STS are both set, an SCI (or
SMI# if SCI_EN is not set) will be generated.
In any sleeping state S1–S5, while PWRBTN_EN (PMBASE + 02h, bit 8) and
PWRBTN_STS are both set, a wake event is generated.
NOTE: If the PWRBTN_STS bit is cleared by software while the PWRBTN# signal is
sell asserted, this will not cause the PWRBN_STS bit to be set. The PWRBTN#
signal must go inactive and active again to set the PWRBTN_STS bit.
7:6
5
Reserved
Global Status (GBL _STS) — R/WC.
0 = The SCI handler should then clear this bit by writing a 1 to the bit location.
1 = Set when an SCI is generated due to BIOS wanting the attention of the SCI
handler. BIOS has a corresponding bit, BIOS_RLS, which will cause an SCI and
set this bit.
Datasheet
463
INTEL [ INTEL ]
