Preliminary
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2.1.12 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.
2.1.13 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.
2.1.14 Timer/Counter (TIMER)
The 16-bit general purpose Timer has 3 compare/capture channels for input capture and compare/Pulse-
Width Modulation (PWM) output.
2.1.15 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.
2.1.16 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.
2.1.17 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
external pins. Response time and thereby also the current consumption can be configured by altering
the current supply to the comparator.
2.1.18 Voltage Comparator (VCMP)
The Voltage Supply Comparator is used to monitor the supply voltage from software. An interrupt can
be generated when the supply falls below or rises above a programmable threshold. Response time and
thereby also the current consumption can be configured by altering the current supply to the comparator.
2.1.19 General Purpose Input/Output (GPIO)
In the EFM32ZG108, there are 17 General Purpose Input/Output (GPIO) pins, which are divided into
ports with up to 16 pins each. These pins can individually be configured as either an output or input. More
advanced configurations like open-drain, filtering and drive strength can also be configured individually
for the pins. The GPIO pins can also be overridden by peripheral pin connections, like Timer PWM
outputs or USART communication, which can be routed to several locations on the device. The GPIO
supports up to 16 asynchronous external pin interrupts, which enables interrupts from any pin on the
device. Also, the input value of a pin can be routed through the Peripheral Reflex System to other
peripherals.
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2013-10-09 - EFM32ZG108FXX - d0063_Rev0.60
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SILICONIMAGE [ Silicon image ]
