ATXMEGA256A3U Datasheet, PDF (9/116 Pages) ATMEL Corporation – 8/16-bit Atmel XMEGA A3U Microcontroller

XMEGA A3U
7. Memories
7.1 Features
7.2 Overview
8386A–AVR–07/11
• Flash Program Memory
– One linear address space
– In-System Programmable
– Self-Programming and Bootloader support
– Application Section for application code
– Application Table Section for application code or data storage
– Boot Section for application code or bootloader code
– Separate read/write protection lock bits for all sections
– CRC Generator support for CRC check of a selectable flash program memory section
• Data Memory
– One linear address space
– Single cycle access from CPU
– SRAM
– EEPROM
Byte and page accessible
Optional memory mapping for direct load and store
– I/O Memory
Configuration and Status registers for all peripherals and modules
16bit-accessible General Purpose Register for global variables or flags
– Bus arbitration
Safe and deterministic handling of priority between CPU, DMA Controller, and other bus
masters
– Separate buses for SRAM, EEPROM, and I/O Memory
Simultaneous bus access for CPU and DMA Controller
• Production Signature Row Memory for factory programmed data
– ID for each microcontroller device type
– Serial number for each device
– Calibration bytes for factory calibrated peripherals
• User Signature Row
– One flash page in size
– Can be read and written from software
– Content is kept after chip erase
The Atmel^® AVR^® architecture has two main memory spaces, the Program Memory and the
Data Memory. Executable code can only reside in the Program Memory, while data can be
stored both in the Program Memory and the Data Memory. The Data Memory includes both
SRAM, and EEPROM Memory for nonvolatile data storage. All memory spaces are linear and
require no memory bank switching.
The available memory size configurations are shown in ”Ordering Information” on page 2. In
addition each device has a Flash memory signature rows for calibration data, device identifica-
tion, serial number etc.
Non Volatile Memory (NVM) spaces can be locked for further write and read/write operations.
This prevents unrestricted access to the application software.
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