...the world's most energy friendly microcontrollers
EFM32LG295 DATASHEET
F256/F128/F64
•
ARM Cortex-M3 CPU platform
• High Performance 32-bit processor @ up to 48 MHz
• Memory Protection Unit
•
Flexible Energy Management System
• 20 nA @ 3 V Shutoff Mode
• 0.4 µA @ 3 V Shutoff Mode with RTC
• 0.65 µA @ 3 V Stop Mode, including Power-on Reset, Brown-out
Detector, RAM and CPU retention
• 0.95 µA @ 3 V Deep Sleep Mode, including RTC with 32.768 kHz
oscillator, Power-on Reset, Brown-out Detector, RAM and CPU
retention
• 63 µA/MHz @ 3 V Sleep Mode
• 211 µA/MHz @ 3 V Run Mode, with code executed from flash
•
256/128/64 KB Flash
•
32 KB RAM
•
93 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 wake-up from Shutoff Mode
•
12 Channel DMA Controller
•
12 Channel Peripheral Reflex System (PRS) for autonomous in-
ter-peripheral signaling
•
Hardware AES with 128/256-bit keys in 54/75 cycles
•
Timers/Counters
• 4× 16-bit Timer/Counter
• 4×3 Compare/Capture/PWM channels
• Dead-Time Insertion on TIMER0
• 16-bit Low Energy Timer
• 1× 24-bit Real-Time Counter and 1× 32-bit Real-Time Counter
• 3× 16/8-bit Pulse Counter
• Watchdog Timer with dedicated RC oscillator @ 50 nA
•
Backup Power Domain
• RTC and retention registers in a separate power domain, avail-
able in all energy modes
• Operation from backup battery when main power drains out
•
External Bus Interface for up to 4×256 MB of external
memory mapped space
• TFT Controller with Direct Drive
•
Communication interfaces
• 3× Universal Synchronous/Asynchronous Receiv-
er/Transmitter
• UART/SPI/SmartCard (ISO 7816)/IrDA/I2S
• 2× Universal Asynchronous Receiver/Transmitter
• 2× Low Energy UART
• Autonomous operation with DMA in Deep Sleep
Mode
2
• 2× I C Interface with SMBus support
• Address recognition in Stop Mode
•
Ultra low power precision analog peripherals
• 12-bit 1 Msamples/s Analog to Digital Converter
• 8 single ended channels/4 differential channels
• On-chip temperature sensor
• 12-bit 500 ksamples/s Digital to Analog Converter
• 2× Analog Comparator
• Capacitive sensing with up to 16 inputs
• 3× Operational Amplifier
• 6.1 MHz GBW, Rail-to-rail, Programmable Gain
• Supply Voltage Comparator
•
Low Energy Sensor Interface (LESENSE)
• Autonomous sensor monitoring in Deep Sleep Mode
• Wide range of sensors supported, including LC sen-
sors and capacitive buttons
•
Ultra efficient Power-on Reset and Brown-Out Detec-
tor
•
Debug Interface
• 2-pin Serial Wire Debug interface
• 1-pin Serial Wire Viewer
• Embedded Trace Module v3.5 (ETM)
•
Pre-Programmed UART Bootloader
•
Temperature range -40 to 85 ºC
•
Single power supply 1.98 to 3.8 V
•
BGA120 package
32-bit ARM Cortex-M0+, Cortex-M3 and Cortex-M4 microcontrollers for:
• Energy, gas, water and smart metering
• Health and fitness applications
• Smart accessories
• Alarm and security systems
• Industrial and home automation
...the world's most energy friendly microcontrollers
1 Ordering Information
Table 1.1 (p. 2) shows the available EFM32LG295 devices.
Table 1.1. Ordering Information
Ordering Code
Flash (kB)
RAM (kB)
Max
Speed
(MHz)
48
48
48
Supply
Voltage
(V)
1.98 - 3.8
1.98 - 3.8
1.98 - 3.8
Temperature
(ºC)
-40 - 85
-40 - 85
-40 - 85
Package
EFM32LG295F64G-E-BGA120
EFM32LG295F128G-E-BGA120
EFM32LG295F256G-E-BGA120
64
128
256
32
32
32
BGA120
BGA120
BGA120
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2 System Summary
2.1 System 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 ener-
gy 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. This section gives a short introduction to each of the modules in general terms and also
shows a summary of the configuration for the EFM32LG295 devices. For a complete feature set and in-
depth information on the modules, the reader is referred to the
EFM32LG Reference Manual.
A block diagram of the EFM32LG295 is shown in Figure 2.1 (p. 3) .
Figure 2.1. Block Diagram
LG295F64/ 128/ 256
Core and Mem ory
Mem ory
Protection
Unit
Clock Managem ent
Aux High Freq.
RC
Oscillator
High Freq.
Crystal
Oscillator
High Freq
RC
Oscillator
Low Freq.
RC
Oscillator
Ultra Low Freq.
Energy Managem ent
Voltage
Regulator
Brown- out
Detector
Back- up
Power
Dom ain
Voltage
Com parator
ARM Cortex
™
M3 processor
-
Power- on
Reset
Flash
Program
Mem ory
RAM
Mem ory
Debug
Interface
w/ ETM
DMA
Controller
Low Freq.
Crystal
Oscillator
RC
Oscillator
32- bit bus
Peripheral Reflex System
Serial Interfaces
USART
Low
Energy
UART
UART
I/ O Ports
Ex t. Bus
Interface
TFT
Driver
General
Purpose
I/ O
Pin
Wakeup
Tim ers and Triggers
Tim er/
Counter
Low Energy
Tim er
Analog Interfaces
ADC
Security
Hardware
AES
LESENSE
Real Tim e
Counter
I
2
C
Ex ternal
Interrupts
Pin
Reset
DAC
Pulse
Counter
Back- up
RTC
Watchdog
Tim er
Analog
Com parator
Operational
Am plifier
2.1.1 ARM Cortex-M3 Core
The ARM Cortex-M3 includes a 32-bit RISC processor which can achieve as much as 1.25 Dhrystone
MIPS/MHz. A Memory Protection Unit with support for up to 8 memory segments is included, as well
as a Wake-up Interrupt Controller handling interrupts triggered while the CPU is asleep. The EFM32
implementation of the Cortex-M3 is described in detail in
EFM32 Cortex-M3 Reference Manual.
2.1.2 Debug Interface (DBG)
This device includes hardware debug support through a 2-pin serial-wire debug interface and an Embed-
ded Trace Module (ETM) for data/instruction tracing. In addition there is also a 1-wire Serial Wire Viewer
pin which can be used to output profiling information, data trace and software-generated messages.
2.1.3 Memory System Controller (MSC)
The Memory System Controller (MSC) is the program memory unit of the EFM32LG microcontroller. The
flash memory is readable and writable from both the Cortex-M3 and DMA. The flash memory is divided
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into two blocks; the main block and the information block. Program code is normally written to the main
block. Additionally, the information block is available for special user data and flash lock bits. There is
also a read-only page in the information block containing system and device calibration data. Read and
write operations are supported in the energy modes EM0 and EM1.
2.1.4 Direct Memory Access Controller (DMA)
The Direct Memory Access (DMA) controller performs memory operations independently of the CPU.
This has the benefit of reducing the energy consumption and the workload of the CPU, and enables
the system to stay in low energy modes when moving for instance data from the USART to RAM or
from the External Bus Interface to a PWM-generating timer. The DMA controller uses the PL230 µDMA
controller licensed from ARM.
2.1.5 Reset Management Unit (RMU)
The RMU is responsible for handling the reset functionality of the EFM32LG.
2.1.6 Energy Management Unit (EMU)
The Energy Management Unit (EMU) manage all the low energy modes (EM) in EFM32LG microcon-
trollers. Each energy mode manages if the CPU and the various peripherals are available. The EMU
can also be used to turn off the power to unused SRAM blocks.
2.1.7 Clock Management Unit (CMU)
The Clock Management Unit (CMU) is responsible for controlling the oscillators and clocks on-board
the EFM32LG. The CMU provides the capability to turn on and off the clock on an individual basis to all
peripheral modules in addition to enable/disable and configure the available oscillators. The high degree
of flexibility enables software to minimize energy consumption in any specific application by not wasting
power on peripherals and oscillators that are inactive.
2.1.8 Watchdog (WDOG)
The purpose of the watchdog timer is to generate a reset in case of a system failure, to increase appli-
cation reliability. The failure may e.g. be caused by an external event, such as an ESD pulse, or by a
software failure.
2.1.9 Peripheral Reflex System (PRS)
The Peripheral Reflex System (PRS) system is a network which lets the different peripheral module
communicate directly with each other without involving the CPU. Peripheral modules which send out
Reflex signals are called producers. The PRS routes these reflex signals to consumer peripherals which
apply actions depending on the data received. The format for the Reflex signals is not given, but edge
triggers and other functionality can be applied by the PRS.
2.1.10 External Bus Interface (EBI)
The External Bus Interface provides access to external parallel interface devices such as SRAM, FLASH,
ADCs and LCDs. The interface is memory mapped into the address bus of the Cortex-M3. This enables
seamless access from software without manually manipulating the IO settings each time a read or write
is performed. The data and address lines are multiplexed in order to reduce the number of pins required
to interface the external devices. The timing is adjustable to meet specifications of the external devices.
The interface is limited to asynchronous devices.
2.1.11 TFT Direct Drive
The EBI contains a TFT controller which can drive a TFT via a 565 RGB interface. The TFT controller
supports programmable display and port sizes and offers accurate control of frequency and setup and
hold timing. Direct Drive is supported for TFT displays which do not have their own frame buffer. In
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that case TFT Direct Drive can transfer data from either on-chip memory or from an external memory
device to the TFT at low CPU load. Automatic alpha-blending and masking is also supported for transfers
through the EBI interface.
2.1.12 Inter-Integrated Circuit Interface (I2C)
The I C module provides an interface between the MCU and a serial I C-bus. It is capable of acting as
both a master and a slave, and supports multi-master buses. Both standard-mode, fast-mode and fast-
mode plus speeds are supported, allowing transmission rates all the way from 10 kbit/s up to 1 Mbit/s.
Slave arbitration and timeouts are also provided to allow implementation of an SMBus compliant system.
2
The interface provided to software by the I C module, allows both fine-grained control of the transmission
process and close to automatic transfers. Automatic recognition of slave addresses is provided in all
energy modes.
2
2
2.1.13 Universal Synchronous/Asynchronous Receiver/Transmitter (US-
ART)
The Universal Synchronous Asynchronous serial Receiver and Transmitter (USART) is a very flexible
serial I/O module. It supports full duplex asynchronous UART communication as well as RS-485, SPI,
MicroWire and 3-wire. It can also interface with ISO7816 SmartCards, IrDA and I2S devices.
2.1.14 Pre-Programmed UART Bootloader
The bootloader presented in application note AN0003 is pre-programmed in the device at factory. Auto-
baud and destructive write are supported. The autobaud feature, interface and commands are described
further in the application note.
2.1.15 Universal Asynchronous Receiver/Transmitter (UART)
The Universal Asynchronous serial Receiver and Transmitter (UART) is a very flexible serial I/O module.
It supports full- and half-duplex asynchronous UART communication.
2.1.16 Low Energy Universal Asynchronous Receiver/Transmitter
(LEUART)
The unique LEUART , the Low Energy UART, is a UART that allows two-way UART communication on
a strict power budget. Only a 32.768 kHz clock is needed to allow UART communication up to 9600 baud/
s. The LEUART includes all necessary hardware support to make asynchronous serial communication
possible with minimum of software intervention and energy consumption.
TM
2.1.17 Timer/Counter (TIMER)
The 16-bit general purpose Timer has 3 compare/capture channels for input capture and compare/Pulse-
Width Modulation (PWM) output. TIMER0 also includes a Dead-Time Insertion module suitable for motor
control applications.
2.1.18 Real Time Counter (RTC)
The Real Time Counter (RTC) contains a 24-bit counter and is clocked either by a 32.768 kHz crystal
oscillator, or a 32.768 kHz RC oscillator. In addition to energy modes EM0 and EM1, the RTC is also
available in EM2. This makes it ideal for keeping track of time since the RTC is enabled in EM2 where
most of the device is powered down.
2.1.19 Backup Real Time Counter (BURTC)
The Backup Real Time Counter (BURTC) contains a 32-bit counter and is clocked either by a 32.768 kHz
crystal oscillator, a 32.768 kHz RC oscillator or a 1 kHz ULFRCO. The BURTC is available in all Energy
Modes and it can also run in backup mode, making it operational even if the main power should drain out.
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