Atmel XMEGA-A1 Xplained Evaluation Board ATAVRXPLAIN ATAVRXPLAIN Data Sheet

 

8267B-AVR-12/10 

The list of sleep modes is defined in 

config_sleepmgr.h

. By default, the sleep 

manager supports the following modes (in the order listed): 

• Idle 

– 

SLEEPMGR_IDLE

 

•  Extended standby – 

SLEEPMGR_ESTDBY

 

• Power-save 

– 

SLEEPMGR_SAVE

 

• Standby 

– 

SLEEPMGR_STDBY

 

• Power-down 

– 

SLEEPMGR_DOWN

 

If your application does not need all sleep modes, the list should be modified to save 
both memory and execution time. Refer to the configuration file (

config_sleepmgr.h

) 

for information on how to modify the list. 

For convenience, a function that disables all the peripherals/modules and enables 
pull-up on all available I/O pins is included. This puts an Atmel

®

 AVR

®

 XMEGA

®

 in the 

least power consuming configuration, with the exception of EEPROM and Flash 
power reduction modes, when nothing but VCC and GND is connected. 

The function, 

LOWPOWER_Init()

, supports all the different XMEGA families (A1, A3, 

A3B, A4) and resides in 

lowpower.c

, 

lowpower.h

 and 

lowpower_macros.h

.  

Since this function is meant for XMEGAs with floating I/O pins, some custom 
configuration may be necessary for measurement in other setups. Refer to 

lowpower_macros.h

 for the actual example code. 

The supplied code examples are meant for current measurements on either the 
Xplain board, or in a setup where only VCC, GND and alternatively an external crystal 
are connected to the device (I/O pins left floating). If the setup differs from these, it 
may be necessary to change the pin configurations. Special considerations are noted 
below. 

To measure on the Xplain evaluation board, the following modifications are necessary 
to reduce power consumption: 

•  Remove all jumpers from the board 
•  Enable pull-down on pin 3 of PORTQ (disables audio amplifier) 
•  Disable the input buffer on pin 1 of PORTB (potentiometer) 
The two last points are done in the Xplain-specific example code. The Xplain board 
features a 32kHz crystal, which is used to clock the RTC to minimize power 
consumption. 

Current measurements are done by connecting an Ampere-meter between the points 
named IXM+ and IXM-. The shunt located between these measurement points must 
be removed. The location of the measurement points and shunt is shown in Figure 6-
1.