ATxmega128A4U Atmel Corporation, ATxmega128A4U Datasheet - Page 439

• Manufacturer Part Number: ATxmega128A4U
• Manufacturer: Atmel Corporation

Specifications of ATxmega128A4U

• Flash (kbytes): 128 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: 7
• 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): 8
• 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

33.11.3.2
33.11.4
33.11.4.1
8331A–AVR–07/11
EEPROM Programming
Read Fuses
Addressing the EEPROM
The Read Fuses command is used to read the Fuses from software.
1.
2.
3.
during self-programming.
The result will be available in the NVM DATA0 register. The CPU is halted during the complete
execution of the command.
The EEPROM can be read and written from application code in any part of the Flash. Its is both
byte and page accessible. This means that either one byte or one page can be written to the
EEPROM at once. One byte is read from the EEPROM during read.
The EEPROM can be accessed through the NVM controller (I/O mapped), similar to the Flash
Program memory, or it can be memory mapped into the Data Memory space to be accessed
similar to SRAM.
When accessing the EEPROM through the NVM Controller, the NVM Address (ADDR) register
is used to address the EEPROM, while the NVM Data (DATA) register is used to store or load
EEPROM data.
For EEPROM page programming the ADDR register can be treated as having two section. The
least significant bits address the bytes within a page, while the most significant bits address the
page within the EEPROM. This is shown in
page (E2BYTE) is held by the bits [BYTEMSB:0] in the ADDR register. The remaining bits
[PAGEMSB:BYTEMSB+1] in the ADDR register holds the EEPROM page address (E2PAGE).
Together E2BYTE and E2PAGE holds an absolute address to a byte in the EEPROM. The size
of E2WORD and E2PAGE will depend on the page and flash size in the device, refer to the
device data sheet for details on this.
Load the NVM ADDR registers with the address to the fuse byte to read.
Load the NVM CMD register with the Read Fuses command.
Set the CMDEX bit in the NVM CTRLA register. This requires the timed CCP sequence
Figure 33-2 on page
Atmel AVR XMEGA AU
440. The byte address in the
439