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MCIMX53SMD Board Hardware User’s Guide, Rev. 0
Freescale Semiconductor
3.20.
Function Buttons
The MCIMX53SMD board provides two user interface buttons, which are discussed below.
3.20.1. POWER Button
In the ‘Power Off’ state, momentarily pressing the POWER button will begin the PMIC power up cycle. The
PMIC supplied voltage rails will come up in the proper sequence to power the i.MX53 processor. When the
processor is fully powered, the boot cycle will be initiated.
In the ‘Power On’ state, momentarily pressing the POWER button will send a signal to a GPIO port for user
defined action, but will not initiate a hardware shutdown.
In the ‘Power On’ state, holding the power button down for more than 5 seconds will result in the PMIC
initiating a shutdown to the ‘Standby’ power condition. This will also be the result from the ‘Power Off’ state
as the PMIC will transition into the ‘Power On’ state and will still see the POWER button as held down.
3.20.2. RESET Button
Pressing the RESET button in the ‘Power On’ state will force the i.MX53 processor to immediately turn off, and
reinitiate a boot cycle from the Processor Power Off state. The RESET button has no effect on the PMIC or the
voltage rails.
Pressing the RESET button when the MCIMX53SMD board is powered off will have no effect.
3.21.
User Interface LED Indicators
There are eight LED status indicators located next to the micro SD card connector. These LEDs have the
following functions:
15V: The 15V status LED (D29) is a Red LED connected directly to the 15V power rail. This LED indicates
that 15V wall power is being properly supplied to the MCIMX53SMD board.
CMOS Run/Charger Now: This status LED (D27) is a Red LED gated by the EIM_D30 (W4) GPIO pin with
two functions. One of these functions is for CMOS running status, the other is dedicated to the status
of charger.
USER Debug/Charger Done: This LED (D32) is a Green LED gated by the PATA_DATA1 (L3) GPIO pin
with two functions. One of these functions is for User debug, the other is dedicated to the status of
charger.
3G Status: The 3G modem status LED (D19) is an Orange LED gated 3G WWLAN pin.
WiFi/BT: The WiFi/Bt status LED (D9, D10). D9 is a Green LED, and as WLAN Active status. D10 is a Blue
LED, and as BT Active status.
3.22.
Li-ION Battery Connector (J12)
The MCIMX53SMD board provides a footprint (J12) that can be used to solder a five-pin connector. The board
has a three-cell Li-ION battery of ~40 Wh. The developer can change it, if needed, and must follow the pin map
of the connector.
3.23.
Back-Up Coin Cell Posts (BT1)
For proper operation, the coin cell posts should be soldered direction to the MCIMX53SMD board. The
DA9053 PMIC will charge the coin cell when Battery or Wall Power is available. When Battery or Wall Power is
removed, the coin cell will provide power only to the RTC power rail (VLDO1), supplying power to the i.MX53
processor. The length of time a coin cell can power the RTC subsystem may vary.
