Energy micro EFM32 Giant Gecko Starter Kit User manual

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USER MANUAL
Starter Kit EFM32GG-STK3700
The EFM32 Giant Gecko Starter Kit is a feature rich platform for evaluation,
prototyping and application development for the EFM32 Giant Gecko MCU family
with the ARM Cortex-M3 CPU core.
Main features:
• Advanced Energy Monitoring provides real-time information about the energy
consumption of an application or prototype design.
• On-board debugger with the possiblity to debug external targets.
• Several sensors, a 160-segment LCD Display, backup domain capacitor and an
on-board NAND Flash.

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1 Introduction
1.1 Description
The EFM32GG-STK3700 is an excellent starting point to get familiar with the EFM32 Giant Gecko
microcontrollers. The kit contains sensors and peripherals demonstrating some of the MCU's many
capabilities. The kit can also serve as a starting point for application development.
1.2 Features
• EFM32GG990F1024 MCU with 1 MB Flash and 128 KB RAM.
• Advanced Energy Monitoring system for precise current tracking.
• Integrated Segger J-Link USB debugger/emulator with debug out functionality.
• 160 segment Energy Micro LCD.
• 20 pin expansion header.
• Breakout pads for easy access to I/O pins.
• Power sources include USB and CR2032 battery.
• 2 user buttons, 2 user LEDs and a touch slider.
• Ambient Light Sensor and Inductive-capacitive metal sensor.
• EFM32 OPAMP footprint.
• 32 MB NAND Flash.
• USB Micro-AB (OTG) connector.
• 0.03F Super Capacitor for backup power domain.
• Crystals for LFXO and HFXO: 32.768kHz and 48.000MHz.
1.3 Getting Started
The first step to get started with your new EFM32GG-STK3700 is to go to
[http://www.energymicro.com/simplicity]
The Simplicity Studio software package contains all the tools, drivers, software examples and
documentation needed to use the EFM32 Giant Gecko Starter Kit Some important tools for use with the
EFM32GG-STK3700 are:
•energyAware Commander
•energyAware Profiler
The energyAware Commander is a tool for updating the kit's firmware, programming the MCU and
launching demos.
The energyAware Profiler is the PC-side interface to the Advanced Energy Monitor. It provides the
possibility to do energy-debugging and profiling of application code.

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2 Kit Block Diagram
An overview of the EFM32 Giant Gecko Starter Kit is shown in Figure 2.1 (p. 3)
Figure 2.1. EFM32GG-STK3700 Block Diagram
32Mx8 NAND
Flash
USB Mini-B
Connector
EFM32 Giant Gecko
Microcontroller
Device/Host
GPIO
EBI
ACMP
LESENSE
LESENSE
Touch Slider
DEBUG
User Buttons
& LEDs
GPIO
EXP Header
LC Sensor
Light Sensor
8x20 Segment LCD
BOARD
CONTROLLER
USB OTG
Connector
UART

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3 Kit Hardware Layout
The layout of the EFM32 Giant Gecko Starter Kit is shown below.
Figure 3.1. EFM32GG-STK3700 hardware layout
Expansion
Header
Debug
Header
EFM32 Reset
Touch
Slider
Ambient
Light Sensor
User Push-buttons
BU Capacitor
EFM32 Debug
LC Sensor
USB
Interface
8x20 Segment
LCD 32MB NAND
Flash
EFM32 Giant
Gecko MCU EFM32
USB
User LEDs
CR2032
Battery
Power Source
Select

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4 Power Supply and Reset
4.1 MCU Power Selection
The EFM32 Giant Gecko MCU on the EFM32GG-STK3700 is designed to be powered by three different
sources:
• Through the on-board debugger.
• Through the EFM32's own USB regulator.
• By a 3V Battery.
Selecting the power source is done with the slide switch in the lower left corner of the board. Figure
Figure 4.1 (p. 5) shows how the different power sources can be selected with the slide switch.
Figure 4.1. EFM32GG-STK3700 Power Switch
3.3V
VMCU
DBG
USB
BAT
USB Mini-B
Connector
Advanced
Energy
Monitor
5V
3V Lithium Battery
(CR2032)
EFM32 Giant
Gecko MCU USB OTG
Connector
USB_VREGI
(5V)
USB_VREGO
(3.3V)
BAT
USB
DBG
With the switch in the DBG position, an on-board low noise LDO with a fixed output voltage of 3.3V
is used to power the MCU. This LDO is again powered from the "J-Link" USB cable. The Advanced
Energy Monitor is now also connected in series, allowing accurate high speed current measurements
and energy debugging/profiling.
With the switch in the USB position, the integrated linear regulator in the EFM32 Giant Gecko MCU is
used to power the rest of the chip as well as the USB PHY. This allows a USB device application where
the MCU acts as a bus powered device.
Finally, with the switch in the BAT position, a 20mm coin cell battery in the CR2032 socket can be used
to power the device.
Note The Advanced Energy Monitor can only measure the current consumption of the EFM32
when the power selection switch is in the DBG position.
4.2 Board Controller Power
The Board Controller is responsible for important features such as the debugger and the Advanced
Energy Monitor, and is powered exclusively through the USB port in the top left corner of the board.
This part of the kit resides on a separate power domain, so a different power source can be selected for
the MCU while retaining debugging functionality. This power domain is also isolated to prevent current
leakage from the MCU power domain when power to the Board Controller is removed.

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4.3 Backup Power Domain
The kit contains a backup capacitor that can be used together with the EFM32 Giant Gecko's backup
power domain. In this case, all other power sources are removed from the kit, and only a small part of
the EFM32 runs off the capacitor. It is also possible to enter backup mode while the Board Controller is
powered by selecting either BAT or USB with no battery in the socket or USB cable in the connector.
4.4 MCU Reset
The EFM32 MCU can be reset by a few different sources:
• The RESET button.
• The on-board debugger.
• An external debugger by pulling the #RST pin low.
4.5 Board Controller Reset
The Board Controller can be reset by removing and re-inserting the J-Link USB cable. Removing the
Board Controller USB cable will not reset the EFM32, but whenever the Board Controller is powered up
again, it will issue a RESET to the EFM32 through the on-board debugger.

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5 Peripherals
The starter kit has a set of peripherals that showcase some of the features of the EFM32 Giant Gecko
microcontroller.
Be aware that most EFM32 I/O routed to peripherals are also routed to the breakout pads. This must be
taken into consideration when using the breakout pads for your application.
5.1 Push Buttons and LEDs
The kit has two user push buttons marked PB0 and PB1. They are connected to the EFM32, and are
debounced by RC filters with a time constant of 1ms. The buttons are connected to pins PB9 and PB10.
In addition to the two push buttons, the kit also features two yellow LEDs marked LED0 and LED1, that
are controlled by GPIO pins on the EFM32. The LEDs are connected to pins PE2 and PE3 in an active-
high configuration.
Figure 5.1. Buttons/LEDs
User Buttons
& LEDs
UIF_LED0
UIF_LED1
UIF_PB0
UIF_PB1
PB9
PB10
PE2
PE3
EFM32 MCU
5.2 LCD
A 28-pin Energy Micro LCD display is connected to the EFM32. The LCD has 8 common lines and 20
segment lines, giving a total of 160 segments in 8-plexed mode. These lines are not shared on the
breakout pads.
Figure 5.2. 160 Segment LCD
PB[2..0]
PA[11..7]
EFM32 MCU
LCD_SEG[39..35]
LCD_SEG[34..32]
LCD_SEG[31..28]
LCD_SEG[19..12]
LCD_COM[7..4]
LCD_COM[3..0]
PD[12..9]
PA[6..0], PA15
PB[6..3]
PE[7..4]
8x20 Segment LCD
Capacitors for the EFM32 Giant Gecko LCD boost function are also available on the EFM32GG-
STK3700.
5.3 Capacitive Touch Slider
A touch slider utilizing the capacitive touch capability is available. It is placed beneath the two push
buttons on the kit. The slider interpolates 4 separate pads to find the exact position of a finger. For low
power operation, the touch slider can be used together with LESENSE to continuously scan all 4 pads,
using LESENSE channels 8 to 11.

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Figure 5.3. Touch Slider
Touch Slider
PC10 (ACMP1_CH2)
PC11 (ACMP1_CH3)
PC8 (ACMP1_CH0)
PC9 (ACMP1_CH1)
UIF_TOUCH0
UIF_TOUCH1
UIF_TOUCH2
UIF_TOUCH3
EFM32 MCU
The capacitive touch slider works by sensing changes in the capacitance of the pads when touched by a
human finger. Sensing the changes in capacitance is done by setting up the touch pad as part of an RC
relaxation oscillator using the EFM32's analog comparator, and then counting the number of oscillations
during a fixed period of time.
5.4 Ambient Light Sensor
The kit has a light sensitive, transistor type, ambient light sensor connected to the low energy sensor
interface of the EFM32 Giant Gecko MCU. The sensor is placed above the push buttons and can be
used to sense changes in ambient light levels.
Figure 5.4. Light Sensor
LIGHT_EXCITE
LIGHT_SENSE
22K
TEMT6200FX01
PD6 (LES_ALTEX0)
PC6 (ACMP0_CH6)
EFM32 MCU
Two pins are used for the light sensor operation: one for excitation, and one for sensing. The sense pin
is connected to ACMP0 CH6. Both the excitation pin and the sense pin can be controlled directly from
the EFM32's LESENSE module.
5.5 LC Sensor
Inthebottomrightcornerthereisaninductive-capacitivesensorfordemonstratingthelowenergysensor
interface. By setting up oscillating currents in the inductor, metal nearby the inductor can be sensed by
measuring the oscillation decay time. The effective range is a few millimeters.
Figure 5.5. LC Metal Sensor
PB12 (DAC0_OUT1)
PC7 (ACMP0_CH7)
EFM32 MCU
100 nF
330 pF
390 uH
1.5K
DAC_LC_EXCITE
LES_LC_SENSE
Metal Object
5.6 NAND Flash
A 32MB NAND Flash is connected to the external bus interface of the EFM32 Giant Gecko MCU. The
interface is a simple 8-bit parallel interface. This peripheral demonstrates the EFM32 Giant Gecko's EBI
module's NAND support with built in ECC generation.

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Figure 5.6. NAND Flash Interface
PD15 NAND_R/B#
PD14 NAND_CE#
PD13 NAND_WP#
PF9 EBI_RE#
PF8 EBI_WE#
PC2 EBI_A25
PC1 EBI_A24
PE[15..8] EBI_AD[7..0]
PB15 NAND_PWR_EN
I/O[7..0]
R/B#
ALE
CLE
WE#
RE#
CE#
WP#
VMCU
EFM32 MCU NAND256W3A
A separate power switch is used to enable/disable the NAND flash, thus avoiding excess current draw
when not used. When NAND_PWR_EN is high, the NAND flash is powered from the same supply as
the EFM32 MCU. It is recommended to keep the write-protect line low during power transitions.
TheALE(addresslatchenable)andCLE(commandlatchenable)pins of the NAND Flash areconnected
to the EBI Address pins 24 and 25, and the CE (chip enable) line is connected to a general GPIO pin.
This causes the NAND data, address and command registers to be mapped in the EFM32's address
space as:
Data register: 0x80000000
Address register: 0x81000000
Command register: 0x82000000
5.7 Backup Domain Capacitor
A small super capacitor is provided to evaluate the EFM32 Giant Gecko MCU's backup power domain.
The capacitor has a nominal value of 33 mF, and is connected with a 100 ohm series resistor to the
BU_VIN pin of the EFM32.
Because of the extremely low power consumption of the EFM32 in backup mode (400nA), the capacitor
can power a clock application using the low frequency crystal oscillator (LFXO) for more than 8 hours.
The series resistor allows measuring of the current drawn from the capacitor into the EFM32 device, by
simply using a multimeter to measure the voltage across it. Please refer to the schematic and assembly
drawings to locate the series resistor.
5.8 USB Micro-AB Connector
The EFM32GG-STK3700 board is equipped with a USB Micro-AB connector supporting USB Device
and Embedded Host modes. The figure below shows how the USB lines are connected to the EFM32.
The USB_VBUSEN line is connected to a current limited switch which supplies the VBUS line with 5V
when operating as a USB Host. The current limited switch also has a flag signal connected to the EFM32
which can notify it in case excessive current is drawn by the attached device. Note that the "J-Link" USB
cable must be inserted to provide 5V to the device when operating the EFM32 in host mode.

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Figure 5.7. EFM32 USB Connector
USB OTG
Connector
PF11 (USB_DP)
PF12 (USB_ID)
PF10 (USB_DM)
PF6 (GPIO)
USB_VBUS
USB_VREGI
USB_VREGO
4.7uF1uF
VBUS Enable
5V
PF5 (USB_VBUSEN)
VBUS
D+
D-
ID
Overcurrent
5.9 Op-Amp Footprint
If the kit is flipped over there is a silk-print model of a typical operational amplifier feedback circuit. The
actual operational amplifier is one of the op-amps inside the EFM32. By soldering 0603 sized resistors
the EFM32 internal operational amplifier can be evaluated with exact resistor values.