SoM-iMX6U User Manual
Revision 1.00 © 2016
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Mechanical and Environmental
Dimensions:
SODIMM form factor with the length dimension extended (2.66" x 1.5")
Power Supply Voltage:
+3.3 Volts DC +/- 5%
Power Requirements (typical):
Typical 3.3 Volts @ 170mA (0.56 watts)
Max current draw during boot process: 300 mA
Constant busy loop: 240 mA
Idle system: 170 mA
APM sleep mode with Ethernet PHY disabled: 3.60 mA
Operating Temperature:
-40 ~ 85° C (-40 ~ 185 ° F), fan-less operation
Operating Humidity:
0% ~ 90% relative humidity, non-condensing
2.2
Real-Time Clock
The SoM-iMX6U has an embedded Real-time Clock. Battery backup is provided from the carrier board
using the VSTBY pin. The SoM-iMX6U will retain the RTT value register during reset and hence use it as a
RTC. The RTC has the provision to set alarms that can interrupt the processor. For example, the
processor can be placed in sleep mode and then later awakened using the alarm function.
2.3
Watchdog Timer
The SoM-iMX6U provides an external Watchdog Timer/ Supervisor (MAX6747) with an extended
watchdog timeout period of 1.42 seconds (±10%). Upon power-up the Watchdog is disabled and does
not require pulsing. To start the Watchdog, it must first be enabled. This is done by configuring port line
CSI_HSYNC as an output and setting it low in software. Once enabled, the Watchdog should be pulsed,
using port line LCD_DATA02, continually every 1.28 seconds or faster to prevent the Watchdog from
timing out and resetting the module. If the user is using the watchdog to force a system reset, the
watchdog may need up to 1.56 seconds of inactivity before the watchdog reset will occur. The watchdog
is automatically disabled upon reset but it can also be disabled by setting CSI_HSYNC high.