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SAM4C32-EK [USER GUIDE]
Atmel-11253A-ATARM-SAM4C32-EK-UserGuide_17-Sep-14
4.2
Measuring the Backup Mode Current Consumption on VDDBU
The SAM4C32 has an ultra-low-power mode RTC and Supply controller allowing less than 1µA (typical) on
VDDBU, with the following functions/peripherals configuration:
32.768 kHz Crystal Oscillator enabled
POR backup on VDDBU disabled
RTC running
RTT enabled on 1 Hz mode
Force wake-up (FWUP) enabled
Anti-tamper Input (TMP0) enabled
To measure the current consumption on VDDBU when in backup mode, JP9 (Shutdown control) must be opened
and an ammeter connected on JP8 (VDDBU) as described in the following procedure:
1.
Power off the board using SW1
2.
Insert the 3V lithium battery provided in the battery holder
3.
Place an ammeter (with sufficient capacity to measure current lower than 1µA) on JP8
4.
Power on the board using SW1
5.
(
optional
) Set the RTC as described above
6.
Press the push button BP5 (SCROLL_DOWN) to place the board in low-power mode
Before shutdown, the following messages are displayed on the LCD:
“ENTERING BACKUP MODE”
“PRESS FWUP BP1 TO WAKE UP”
“USE BP3 TO GENERATE TAMPER EVENTS”
Blinking “BYE”
At this point, the current consumption on the ammeter should be less than 1µA @ 25°C @ 3V.
Once in backup mode, the anti-tamper pin 0 (TMP0) is enabled. The BP3 (TMP0) push button can be used to
generate tamper events before waking up the board. Tamper events are registered without waking up the board.
Up to 15 tamper events can be registered. To wake up the board, press BP1 (FWUP). Upon start-up, the number
of tamper events and time-stamping of the tamper events are displayed on the LCD.
5.
SAM4C32-EK Design Files
5.1
SAM4C32-EK Schematics
This section contains the schematics for the SAM4C32-EK (Rev. A).
Main page with Block Diagram
Information regarding the design
SAM4C32 Microcontroller and its crystals, decoupling capacitors and analog inputs
Power Supplies Distribution
RS232, RS485 and DBGU Interfaces, TWI Memories, and Temperature Sensor
Custom Glass LCD and ZigBee, XPRO interfaces
User Buttons, I/O expansion headers and JTAG Interfaces
