SMARC-sXEL - User Guide Rev. 1.0
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If power is removed, the wake-up event (S0) requires VDD_IN to power on the module.
8.3.2.
Power Button (POWER_BTN#)
The power button (Pin-P128) is available through the SMARC connector. To start the module using the Power Button
the PWRBTN# signal must be at least 50 ms (50 ms ≤ t < 4 s, typical 400 ms) at low level (Power Button Event).
Pressing the power button for at least 4 seconds turns off power to the module (Power
Button Override)
8.3.3.
Power Management Signals
The power supply control settings are set in the BIOS and enable the module to shut down, rest and wake from
standby properly.
Table 34: Power Management Pins
SMARC Signal
SMARC Pin Description
CARRIER_PWR_ON
S154
Carrier Board circuits (apart from power management and power path
circuits) should not be powered up until the Module asserts the
CARRIER_PWR_ON signal.
CARRIER_STBY#
S152
Module drives this signal low when the system is in a standby power state
CHARGER_PRSNT#
S-152
Held low by Carrier if DC input for battery charger is present.
Charging#
S-151
Held low by Carrier during battery charging. Carrier to float the line when
charge is complete.
POWER_BTN#
P128
Power-button input from Carrier Board. Carrier to float the line in in-active
state. Active low, level sensitive. Should be debounced on the Module.
LID#
S148
Lid open/close indication to Module. Low indicates lid closure (which
system may use to initiate a sleep state). Carrier to float the line in inactive
state. Active low, level sensitive. Should be de-bounced on the Module.
SLEEP#
S149
Sleep indicator from Carrier Board. May be sourced from user Sleep button
or Carrier logic. Carrier to float the line in in-active state. Active low, level
sensitive. Should be debounced on the Module
RESET_OUT#
P126
General purpose reset output to Carrier Board
RESET_IN#
P127
Reset input from Carrier Board. Carrier drives low to force a Module reset,
floats the line otherwise. This signal is level triggered during bootup stop
booting of the module. After bootup it acts as an edge triggered signal.
VIN_PWR_BAD#
S150
Power bad indication from Carrier Board. Module and Carrier power supplies
(other than Module and Carrier power supervisory circuits) are not be
enabled while this signal is held low by the Carrier.
BATLOW#
S156
Battery low indication to Module. Carrier to float the line in inactive state.
I2C_PM_DAT
P122
Power management I2C bus DATA
I2C_PM_CK
P121
Power management I2C bus CLK
SMB_ALERT#
P1
SMBus Alert# (Interrupt) Signal
TEST#
S157
Held Low by Carrier to Invoke Module Vendor Specific Test Functions