EFM32ZG222 Datasheet, PDF (5/66 Pages) Silicon image – Energy, gas, water and smart metering

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 LEUART^TM, 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 Analog to Digital Converter (ADC)
The ADC is a Successive Approximation Register (SAR) architecture, with a resolution of up to 12 bits
at up to one million samples per second. The integrated input mux can select inputs from 4 external
pins and 6 internal signals.
2.1.20 Current Digital to Analog Converter (IDAC)
The current digital to analog converter can source or sink a configurable constant current, which can
be output on, or sinked from pin or ADC. The current is configurable with several ranges of various
step sizes.
2013-10-09 - EFM32ZG222FXX - d0066_Rev0.60
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