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EFM32HG308 Datasheet, PDF (5/54 Pages) Silicon Laboratories – Output state retention and wake-up from Shutoff Mode
Preliminary
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2.1.11 Inter-Integrated Circuit Interface (I2C)
The I2C module provides an interface between the MCU and a serial I2C-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.
The interface provided to software by the I2C 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.
2.1.12 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.
2.1.13 Pre-Programmed USB/UART Bootloader
The bootloader presented in application note AN0042 is pre-programmed in the device at factory. The
bootloader enables users to program the EFM32 through a UART or a USB CDC class virtual UART
without the need for a debugger. The autobaud feature, interface and commands are described further
in the application note.
2.1.14 Low Energy Universal Asynchronous Receiver/Transmitter
(LEUART)
The unique LEUARTTM, 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.
2.1.15 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.
2.1.16 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.
2.1.17 Pulse Counter (PCNT)
The Pulse Counter (PCNT) can be used for counting pulses on a single input or to decode quadrature
encoded inputs. It runs off either the internal LFACLK or the PCNTn_S0IN pin as external clock source.
The module may operate in energy mode EM0 - EM3.
2.1.18 Analog Comparator (ACMP)
The Analog Comparator is used to compare the voltage of two analog inputs, with a digital output indi-
cating which input voltage is higher. Inputs can either be one of the selectable internal references or from
2015-05-06 - EFM32HG308FXX - _Rev0.91
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