ATXMEGA128A4 Datasheet, PDF (8/69 Pages) ATMEL Corporation – 8/16-bit XMEGA A4 Microcontroller

XMEGA A4
7. Memories
7.1 Features
7.2 Overview
• 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 lock bits and protection for all sections
• Data Memory
– One linear address space
– Single cycle access from CPU
– SRAM
– EEPROM
Byte or 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 Register for global variables or flags
– External Memory support
– Bus arbitration
Safe and deterministic handling of CPU and DMA Controller priority
– Separate buses for SRAM, EEPROM, I/O Memory and External Memory access
Simultaneous bus access for CPU and DMA Controller
• Calibration Row Memory for factory programmed data
Oscillator calibration bytes
Serial number
Device ID for each device type
• User Signature Row
One flash page in size
Can be read and written from software
Data is kept after Chip Erase
The AVR architecture has two main memory spaces, the Program Memory and the Data Mem-
ory. In addition, the XMEGA A4 features an EEPROM Memory for non-volatile data storage. All
three memory spaces are linear and require no paging. The available memory size configura-
tions are shown in ”Ordering Information” on page 2. In addition each device has a Flash
memory signature row for calibration data, device identification, serial number etc.
Non-volatile memory spaces can be locked for further write or read/write operations. This pre-
vents unrestricted access to the application software.
7.3 In-System Programmable Flash Program Memory
The XMEGA A4 devices contains On-chip In-System Programmable Flash memory for program
storage, see Figure 7-1 on page 9. Since all AVR instructions are 16- or 32-bits wide, each Flash
address location is 16 bits.
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8069C–AVR–06/08