Preliminary
...the world's most energy friendly microcontrollers
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-M0+, innovative low energy techniques, short wake-up time from
energy saving modes, and a wide selection of peripherals, the EFM32ZG 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 EFM32ZG108 devices. For a complete feature set and in-
depth information on the modules, the reader is referred to the EFM32ZG Reference Manual.
A block diagram of the EFM32ZG108 is shown in Figure 2.1 (p. 3) .
Figure 2.1. Block Diagram
ZG108F32/ 16/ 8/ 4
Energy Management
Core and Memory
Clock Management
High Freq
Crystal
Oscillator
High Freq
RC
Oscillator
Voltage
Regulator
Voltage
Comparator
ARM Cortex™M0+ processor
Low Freq
Crystal
Oscillator
Low Freq
RC
Oscillator
Power- on
Reset
Brown- out
Detector
Flash
Program
Memory
RAM
Memory
Debug
Interface
DMA
Controller
Ultra Low Freq
RC
Oscillator
32- bit bus
Peripheral Reflex System
Serial Interfaces
I/ O Ports
Timers and Triggers
Analog Interfaces
General
External
Analog
USART
I2C
Purpose
Timer/
Counter
Real Time
Counter
Comparator
Interrupts
I/ O
Low
Energy
Uart™
Pin
Pin
Pulse
Counter
Watchdog
Timer
Reset
Wakeup
2.1.1 ARM Cortex-M0+ Core
The ARM Cortex-M0+ includes a 32-bit RISC processor which can achieve as much as 0.9 Dhrystone
MIPS/MHz. A Wake-up Interrupt Controller handling interrupts triggered while the CPU is asleep is in-
cluded as well. The EFM32 implementation of the Cortex-M0+ is described in detail in ARM Cortex-M0+
Devices Generic User Guide.
2.1.2 Debug Interface (DBG)
This device includes hardware debug support through a 2-pin serial-wire debug interface.
2.1.3 Memory System Controller (MSC)
The Memory System Controller (MSC) is the program memory unit of the EFM32ZG microcontroller.
The flash memory is readable and writable from both the Cortex-M0+ and DMA. The flash memory is
divided 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.
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2013-10-09 - EFM32ZG108FXX - d0063_Rev0.60
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