XMEGA A4U [DATASHEET]
Atmel-8387G-AVR-ATxmega16A4U-34A4U-64A4U-128A4U-Datasheet_03/2014
12
7.
Memories
7.1
Features
Flash program memory
One linear address space
In-system programmable
Self-programming and boot loader support
Application section for application code
Application table section for application code or data storage
Boot section for application code or boot loader code
Separate read/write protection lock bits for all sections
Built in fast 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
16 bit-accessible general purpose registers for global variables or flags
Bus arbitration
Deterministic priority handling 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
7.2
Overview
The Atmel AVR architecture has two main memory spaces, the program memory and the data memory. Executable
code can reside only in the program memory, while data can be stored in the program memory and the data memory.
The data memory includes the internal SRAM, and EEPROM for nonvolatile data storage. All memory spaces are
linear and require no memory bank switching. Nonvolatile memory (NVM) spaces can be locked for further write and
read/write operations. This prevents unrestricted access to the application software.
A separate memory section contains the fuse bytes. These are used for configuring important system functions, and
can only be written by an external programmer.
a Flash memory signature row for calibration data, device identification, serial number etc.