ATXMEGA256A3_10 Datasheet, PDF (13/110 Pages) ATMEL Corporation – 8/16-bit AVR XMEGA A3 Microcontroller

XMEGA A3
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 A3 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 A3 devices.
Device
ATxmega64A3
ATxmega128A3
ATxmega192A3
ATxmega256A3
Byte 2
42
42
44
42
Device ID bytes
Byte 1
96
97
97
98
Byte 0
1E
1E
1E
1E
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.
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8068R–AVR–08/10