
12
INTEL
PENTIUM
II PROCESSOR MOBILE MODULE MMC-1
3.1.5
Power Management (8 Signals)
Table 5 lists the power management interface signals. The
SM_CLK and SM_DATA signals refer to the two-wire serial
SMBus interface. Although this interface is currently used
solely for the digital thermal sensor, the SMBus contains
reserved serial addresses for future use. See section 4.9 for
more details.
Table 5. Power Management Signal Descriptions
Voltage
Name
Type
Description
OEM_PU
I
CMOS
V_3
OEM Pullup:
This pullup resistor is not required on the Intel
Pentium
II processor mobile module. This signal is used by
previous Intel mobile module generations.
L2_ZZ
N/C
CMOS
V_CPUIO
Low-Power Mode For Cache SRAM:
This signal is not used on
the Intel
Pentium
II processor mobile module. It is a signal
used by previous Intel mobile module generations.
SUS_STAT#
I
CMOS
V_3ALWAYS
1
Suspend Status:
This signal connects to the SUS_STAT1#
output of PIIX4E. It provides information on host clock status and
is asserted during all suspend states.
VR_ON
I
V_3S
VR_ON:
Voltage regulator ON.
This 3.3V (5V tolerant) signal
controls the operation of the voltage regulator.
VR_ON should be
generated as a function of the PIIX4E SUSB# signal which is
used for controlling the “Suspend State B” voltage planes. This
signal should be driven by a digital signal with a rise/fall time of
less than or equal to 1 us. (VIL (max)=0.4V, VIH (min)=3.0V).
See Figure 5 for proper sequencing of VR_ON.
VR_PWRGD
O
V_3S
VR_PWRGD:
This signal is driven high to indicate that the
voltage regulator is stable and is pulled low using a 100K resistor
when inactive.
It can be used in some combination to generate
the system PWRGOOD signal.
SM_CLK
I/O D
CMOS
V_3
Serial Clock:
This clock signal is used on the SMBus interface
to the digital thermal sensor. Ensure proper termination based
upon the
System Management Bus Specification, Revision 1.0
.
SM_DATA
I/O D
CMOS
V_3
Serial Data:
Open-drain data signal on the SMBus interface to
the digital thermal sensor. Ensure proper termination based upon
the
System Management Bus Specification, Revision 1.0
.
ATF_INT#
O D
CMOS
V_3
ATF Interrupt:
This signal is an open-drain output signal of the
digital thermal sensor.
NOTE:
V_3ALWAYS: 3.3V supply. It is generated whenever V_DC is available and supplied to PIIX4E resume well.