IBASE Technology ET976, Design Manual

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COM Express® Carrier Board Design Guide 63
Table 20: Power Management Signal Descriptions
Signal Pin Description I/O Remarks
PWRBTN# B12
Power button low active signal used to wake
up the system from S5 state (soft off). This
signal is triggered on the falling edge.
I 3.3V
Suspend
CMOS Drive with >=10mA
SYS_RESET# B49 Reset button input. Active low request for
Module to reset and reboot. May be falling
edge sensitive. For situations when
SYS_RESET# is not able to reestablish control
of the system, PWR_OK or a power cycle may
be used. I 3.3V
Suspend
CMOS Drive with >=10mA
CB_RESET# B50 Reset output signal from Module to Carrier
Board. This signal may be driven low by the
Module to reset external components located
on the Carrier Board. O 3.3V
Suspend
CMOS
PWR_OK B24 Power OK status signal generated by the ATX
power supply to notify the Module that the DC
operating voltages are within the ranges
required for proper operation. I 3.3V
CMOS
SUS_STAT# B18 Suspend status signal to indicate that the
system will be entering a low power state soon.
It can be used by other peripherals on the
Carrier Board as an indication that they should
go into power-down mode. O 3.3V
Suspe
nd
CMOS
SUS_S3# A15 S3 Sleep control signal indicating that the
system resides in S3 state (Suspend to
RAM). O 3.3V
Suspend
CMOS This signal can be used
to control the ATX
power supply via the
'PS_ON#'
signal.
SUS_S4# A18
S4 Sleep control signal indicating that the
system resides in S4 state (Suspend to
Disk). O 3.3V
Suspend
CMOS
SUS_S5# A24 S5 Sleep Control signal indicating that the
system resides in S5 State (Soft Off).
O 3.3V
Suspend
CMOS
WAKE0# B66 PCI Express wake-up event signal.
I 3.3V
Suspend
CMOS
WAKE1# B67 General purpose wake-up signal.
I 3.3V
Suspend
CMOS
BATLOW# A27 Battery low input. This signal may be driven
low by external circuitry to signal that the
system battery is low. It also can be used
t
i l th t l
I 3.3V
Suspend
CMOS