ATxmega128B1 Atmel Corporation, ATxmega128B1 Datasheet - Page 295

• Manufacturer Part Number: ATxmega128B1
• Manufacturer: Atmel Corporation

Specifications of ATxmega128B1

• Flash (kbytes): 128 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 53
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Segment Lcd: 160
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 16
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 4
• Resistive Touch Screen: No
• 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: 3
• Output Compare Channels: 10
• Input Capture Channels: 10
• Pwm Channels: 10
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

23.3
23.4
23.5
8291A–AVR–10/11
Operation
CRC on Flash memory
CRC on DMA Data
The data source for the CRC module must be selected in software as either flash memory, the
DMA channels, or the I/O interface. The CRC module then takes data input from the selected
source and generates a checksum based on these data. The checksum is available in the
CHECKSUM registers in the CRC module.
For the I/O interface or DMA controller, which CRC polynomial is used is software selectable.
The default setting is CRC-16. For CRC with flash memory, only CRC-32 can be used. The CRC
module operates on bytes only.
Figure 23-1. CRC generator block diagram.
A CRC-32 calculation can be performed on the entire flash memory, on only the application sec-
tion, on only the boot section, or on a software selectable range of the flash memory. Other than
selecting the flash as the source, all further control and setup are done from the NVM controller.
This means that the NVM controller configures the memory range to perform the CRC on, and
the CRC is started using NVM commands. Once completed, the result is available in the check-
sum registers in the CRC module. For further details on setting up and performing CRC on flash
memory, refer to
CRC-16 or CRC-32 calculations can be performed on data passing through any DMA channel.
Once a DMA channel is selected as the source, the CRC module will continuously generate the
”Memory Programming” on page
DATAIN
CTRL
crc32
8
CRC-16
Checksum read
16
Controller
CHECKSUM
bit-reverse +
complement
DMA
383.
8
Atmel AVR XMEGA B
CRC-32
Memory
32
Flash
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