ATxmega64A4U Atmel Corporation, ATxmega64A4U Datasheet - Page 432

• Manufacturer Part Number: ATxmega64A4U
• Manufacturer: Atmel Corporation

Specifications of ATxmega64A4U

• Flash (kbytes): 64 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 34
• Ext Interrupts: 34
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Twi (i2c): 2
• Uart: 5
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 2
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.6 to 3.6
• Operating Voltage (vcc): 1.6 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 5
• Output Compare Channels: 16
• Input Capture Channels: 16
• Pwm Channels: 16
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

33.11 Self-Programming and Boot Loader Support
33.11.1
33.11.1.1
33.11.1.2
8331A–AVR–07/11
Flash Programming
Application and Boot Loader sections
Addressing the Flash
Reading and writing the EEPROM and Flash memory from the application software in the device
is referred to as self-programming. A Boot Loader (application code located in the Boot Loader
Section of the Flash) can both read and write the Flash Program Memory, User Signature Row
and EEPROM, and write the Lock Bits to a more secure setting. Application code in the applica-
tion section can read from the Flash, User Signature row, Calibration row and Fuses, and read
and write the EEPROM.
The Boot Loader support provides a real Read-While-Write self-programming mechanism for
uploading program new code by the device itself. This feature allows flexible application soft-
ware updates controlled by the device using a Boot Loader application that reside in the Boot
Loader Section in the Flash. The Boot Loader can use any available communication interface
and associated protocol to read code and write (program) that code into the Flash memory, or
read out the program memory code. It has the capability to write into the entire Flash, including
the Boot Loader Section. The Boot Loader can thus modify itself, and it can also erase itself from
the code if the feature is not needed anymore.
The Application and Boot Loader sections in the Flash are different when it comes to self-
programming.
The User Signature Row section has the same properties as the Boot Loader Section.
Table 33-1.
The Z-pointer is used to hold the Flash memory address for read and write access. For more
details on the Z-pointer refer to
Since the Flash is word accessed and organized in pages, the Z-pointer can be treated as hav-
ing two sections. The least significant bits address the words within a page, while the most
significant bits address the page within the Flash. This is shown in
word address in the page (FWORD) is held by the bits [WORDMSB:1] in the Z-pointer. The
remaining bits [PAGEMSB:WORDMSB+1] in the Z-pointer holds the Flash page address
(FPAGE). Together FWORD and FPAGE holds an absolute address to a word in the Flash.
Section being addressed during the
programming?
Application Section
Boot Loader Section
User Signature Row section
– When erasing or writing a page located inside the Application Section, the Boot
– When erasing or writing a page located inside the Boot Loader Section, the CPU is
Loader Section can be read during the operation, thus the CPU can run and execute
code from the Boot Loader Section.
halted during the entire operation and code cannot execute.
Summary of self-programming functionality
”The X-, Y-, and Z- Registers” on page
Section that can be read during
programming
Boot Loader Section
None
None
Atmel AVR XMEGA AU
Figure 33-1 on page
10.
CPU Halted?
No
Yes
Yes
433. The
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