EFM32WG Datasheet, PDF (15/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.

...the world's most energy friendly microcontrollers
5 Memory and Bus System
0123 4
ARM Cort e x-M 4
DM A Cont rolle r
5.1 Introduction
Fla sh
RAM
EBI
Peripherals
What?
Quick Facts
A low latency memory system, including low
energy flash and RAM with data retention,
makes extended use of low-power energy-
modes possible.
Why?
RAM retention reduces the need for storing
data in flash and enables frequent use of the
ultra low energy modes EM2 and EM3 with
as little as 0.65 µA current consumption.
How?
Low energy and non-volatile flash memory
stores program and application data
in all energy modes and can easily be
reprogrammed in system. Low leakage RAM,
with data retention in EM0 to EM3, removes
the data restore time penalty, and the DMA
ensures fast autonomous transfers with
predictable response time.
The EFM32WG contains an AMBA AHB Bus system allowing bus masters to access the memory
mapped address space. A multilayer AHB bus matrix, using a Round-robin arbitration scheme, connects
the master bus interfaces to the AHB slaves (Figure 5.1 (p. 16) ). The bus matrix allows several AHB
slaves to be accessed simultaneously. An AMBA APB interface is used for the peripherals, which are
accessed through an AHB-to-APB bridge connected to the AHB bus matrix. The AHB bus masters are:
• Cortex-M4 ICode: Used for instruction fetches from Code memory (0x00000000 - 0x1FFFFFFF).
• Cortex-M4 DCode: Used for debug and data access to Code memory (0x00000000 - 0x1FFFFFFF).
• Cortex-M4 System: Used for instruction fetches, data and debug access to system space
(0x20000000 - 0xDFFFFFFF).
• DMA: Can access entire memory space (0x00000000 - 0xDFFFFFFF).
• USB DMA: Can access code space, SRAM and EBI (0x00000000 - 0x3FFFFFFF, 0x80000000 -
0xDFFFFFFF), and the peripherals: USB and AES.
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
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