Memory System

Quick Facts

What?

The EFM32 has a low latency memory system which includes low power Flash and RAM with data retention which makes operation in the low energy modes attractive.

Why?

RAM retention reduces the need for storing data in Flash and enables frequent use of the ultra low EM2 and EM3 energy modes.

How?

Low power, non-volatile Flash and low leakage RAM memory stores program and application data in all energy modes and can easily be reprogrammed in system. RAM retention removes the data restore penalty, and the DMA ensures fast transfers and response time.

Features

The EFM32 contains 4 main memory segments which can be accessed by the ARM Cortex-M3 CPU or the DMA controller.

• Flash
• RAM
• External Bus Interface
• Peripherals
• The Low energy peripherals are memory mapped and operate with very low power consumption

Flash Memory

The Flash memory contains the MCU program memory. Additionally, constants used by the program may be placed in Flash and read through software or the DMA. The Flash memory is typically programmed through the debug-interface. Additionally, it may be updated by software, e.g. to store status information or to upgrade the software image.

RAM Memory

The RAM data memory is used by the MCU to store data and variables. Additionally, it is possible to execute instructions from RAM, and the DMA may be set up to transfer data to/from RAM. The RAM retention is available in the low energy modes including EM3.