...the world's most energy friendly microcontrollers
2012-05-02 - Leopard Gecko Family - d0183_Rev0.95 1
www.energymicro.com
EFM32LG Reference Manual
"Leopard Gecko" Series
Preliminary
• 32-bit ARM Cortex-M3 processor running at up to 48 MHz
• Up to 256 KB Flash and 32 KB RAM memory
• Energy efficient and autonomous peripherals
• Ultra low power Energy Modes with Sub µ operation
• Fast wake-up time of only 2 µs
The EFM32LG microcontroller series revolutionizes the 8- to 32-bit market with a
combination of unmatched performance and ultra low power consumption in both
active- and sleep modes. EFM32LG devices consume as little as 200 µA/MHz in run
mode.
EFM32LG's low energy consumption outperforms any other available 8-, 16-,
and 32-bit solution. The EFM32LG includes autonomous and energy efficient
peripherals, high overall chip- and analog integration, and the performance of the
industry standard 32-bit ARM Cortex-M3 processor.
...the world's most energy friendly microcontrollers
2012-05-02 - Leopard Gecko Family - d0183_Rev0.95 2
www.energymicro.com
1 Energy Friendly Microcontrollers
1.1 Typical Applications
The EFM32LG Leopard Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive
applications. The devices are developed to minimise the product of power and time over all phases
of MCU operation. This unique combination of ultra low energy consumption and the performance of
the 32-bit ARM Cortex-M3 processor helps designers get more out of the available energy source in a
variety of applications.
Ultra low energy EFM32LG microcontrollers are perfect for:
• Gas metering
• Energy metering
• Water metering
• Smart metering
• Alarm and security systems
• Health and fitness applications
• Industrial and home automation
0
1 2 3 4
1.2 EFM32LG Development
Because EFM32LG use the Cortex-M3 CPU, embedded designers benefit from a large existing
ecosystem of industry standard development. The development suite spans the whole design process
and includes powerful debug tools and some of the world’s top brand compilers. Libraries with
documentation and user examples shorten time from idea to market release.
The range of EFM32LG devices ensures easy migration and feature upgrade possibilities.
...the world's most energy friendly microcontrollers
2012-05-02 - Leopard Gecko Family - d0183_Rev0.95 3
www.energymicro.com
2 About This Document
This document contains reference material for the EFM32LG series of microcontrollers. All modules and
peripherals in the EFM32LG series devices are described in general terms. Not all modules are present
in all devices and the feature set for each device might vary. Such differences, including pinout, are
covered in the device-specific datasheets.
2.1 Conventions
Register Names
Register names are given with a module name prefix followed by the short register name:
TIMERn_CTRL - Control Register
The "n" denotes the module number for modules which can exist in more than one instance.
Some registers are grouped which leads to a group name following the module prefix:
GPIO_Px_DOUT - Port Data Out Register
The "x" denotes the port instance (A,B,...)
Bit Fields
Registers contain one or more bit fields which can be 1 to 32 bits wide. Bit fields wider than 1 bit are
given with start and stop bit (x:y).
Address
The address for each register can be found by adding the modules base address (found in Memory
Map), with the offset address for the register (found in module Register Map).
Access Type
The register access types used in the register descriptions are explained in Table 2.1 (p. 3) .
Table 2.1. Register Access Types
Access Type Description
R Read only. Writes are ignored
RW Readable and writable
RW1 Readable and writable. Only writes to 1 have effect
W1 Read value undefined. Only writes to 1 have effect
W Write only. Read value undefined.
RWH Readable, writable and updated by hardware
Number format
0x prefix is used for hexadecimal numbers
0b prefix is used for binary numbers
Numbers without prefix are in decimal representation.
Reserved
...the world's most energy friendly microcontrollers
2012-05-02 - Leopard Gecko Family - d0183_Rev0.95 4
www.energymicro.com
Registers and bit fields marked with reserved are reserved for future use. These should be written to 0
unless otherwise stated in the Register Description. Reserved bits might be read as 1 in future devices.
Reset Value
The reset value denotes the value after reset.
Registers denoted with X have unknown value out of reset and need to be initialized before use. Note that
read-modify-write operations on these registers before they are initialized results in undefined register
values.
Pin Connections
Pin connections are given with a module prefix followed by a short pin name:
USn_TX (USART n TX pin)
The location for the pin names given in the module documentation can be found in the device-specific
datasheet.
2.2 Related Documentation
Further documentation on the EFM32LG family and the ARM Cortex-M3 can be found at the Energy
Micro and ARM web pages:
www.energymicro.com
www.arm.com
...the world's most energy friendly microcontrollers
2012-05-02 - Leopard Gecko Family - d0183_Rev0.95 5
www.energymicro.com
3 System Overview
3.1 Introduction
The EFM32 MCUs are the world’s most energy friendly microcontrollers. With a unique combination
of the powerful 32-bit ARM Cortex-M3, innovative low energy techniques, short wake-up time from
energy saving modes, and a wide selection of peripherals, the EFM32LG microcontroller is well suited
for any battery operated application as well as other systems requiring high performance and low-energy
consumption, see Figure 3.1 (p. 7) .
3.2 Features
• ARM Cortex-M3 CPU platform
• High Performance 32-bit processor @ up to 48 MHz
• Memory Protection Unit
• Wake-up Interrupt Controller
• Flexible Energy Management System
• 20 nA @ 3 V Shutoff Mode
• 0.4µA @ 3 V Shutoff Mode with RTC
• 0.9 µA @ 3 V Stop Mode, including Power-on Reset, Brown-out Detector, RAM and CPU
retention
• 1.2 µA @ 3 V Deep Sleep Mode, including Real Time Clock with 32.768 kHz oscillator,
Power-on Reset, Brown-out Detector, RAM and CPU retention
• 50 µA/MHz @ 3 V Sleep Mode
• 200 µA/MHz @ 3 V Run Mode, with code executed from flash
• 256/128/64 KB Flash
• 32 KB RAM
• Up to 90 General Purpose I/O pins
• Configurable Push-pull, Open-drain, pull-up/down, input filter, drive strength
• Configurable peripheral I/O locations
• 16 asynchronous external interrupts
• Output state retention and wakeup from Shutoff Mode
• 12 Channel DMA Controller
• Alternate/primary descriptors with scatter-gather/ping-pong operation
• 12 Channel Peripheral Reflex System for autonomous inter-peripheral signaling
• External Bus Interface for up to 256 MB of external memory mapped space
• TFT Controller supporting Direct Drive
• Universal Serial Bus (USB) with Host and OTG support
• Fully USB 2.0 compliant
• On-chip PHY and embedded 5V to 3.3V regulator
• Integrated LCD Controller for up to 8×36 segments
• Voltage boost, adjustable contrast adjustment and autonomous animation feature
• Hardware AES with 128/256-bit keys in 54/75 cycles
• Communication interfaces
• 3× Universal Synchronous/Asynchronous Receiver/Transmitter
• UART/SPI/SmartCard (ISO 7816)/IrDA (USART0)/I2S (USART1+USART2)
• Triple buffered full/half-duplex operation
• 4-16 data bits
• 2× Universal Asynchronous Receiver/Transmitter
• Triple buffered full/half-duplex operation
• 8-9 data bits
• 2× Low Energy UART
