Datasheet

13
8069R–AVR–06/2013
XMEGA A4
Not recommended for new designs -
Use XMEGA A4U series
7.4.3 EEPROM Data Memory
The XMEGA A4 devices have internal EEPROM memory for non-volatile data storage. It is
addressable either in a separate data space or it can be memory mapped into the normal data
memory space. The EEPROM memory supports both byte and page access.
7.5 Production Signature Row
The Production Signature Row is a separate memory section for factory programmed data. It
contains calibration data for functions such as oscillators and analog modules.
The production signature row also contains a device ID that identify each microcontroller device
type, and a serial number that is unique for each manufactured device. The device ID for the
available XMEGA A4 devices is shown in Table 7-1 on page 13. The serial number consist of
the production LOT number, wafer number, and wafer coordinates for the device.
The production signature row can not be written or erased, but it can be read from both applica-
tion software and external programming.
Table 7-1. Device ID bytes for XMEGA A4 devices.
7.6 User Signature Row
The User Signature Row is a separate memory section that is fully accessible (read and write)
from application software and external programming. The user signature row is one flash page
in size, and is meant for static user parameter storage, such as calibration data, custom serial
numbers or identification numbers, random number seeds etc. This section is not erased by
Chip Erase commands that erase the Flash, and requires a dedicated erase command. This
ensures parameter storage during multiple program/erase session and on-chip debug sessions.
Device Device ID bytes
Byte 2Byte 1Byte 0
ATxmega16A4 41 94 1E
ATxmega32A4 41 95 1E
ATxmega64A4 46 96 1E
ATxmega128A4 46 97 1E