10
XMEGA A3BU [DATASHEET]
8362F–AVR–02/2013
Six of the 32 registers can be used as three 16-bit address register pointers for data space addressing, enabling efficient
address calculations. One of these address pointers can also be used as an address pointer for lookup tables in flash
program memory.
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.
Flash memory signature row for calibration data, device identification, serial number etc.