ATxmega64B3 Atmel Corporation, ATxmega64B3 Datasheet - Page 155

• Manufacturer Part Number: ATxmega64B3
• Manufacturer: Atmel Corporation

Specifications of ATxmega64B3

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 36
• Ext Interrupts: 36
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Segment Lcd: 100
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 2
• Resistive Touch Screen: No
• 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: 2
• Output Compare Channels: 6
• Input Capture Channels: 6
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

13.6
13.6.1
8291A–AVR–10/11
Counter Operation
Normal Operation
Figure 13-4. Period and compare double buffering.
When the CC channels are used for a capture operation, a similar double buffering mechanism
is used, but in this case the buffer valid flag is set on the capture event, as shown in
For capture, the buffer register and the corresponding CCx register act like a FIFO. When the
CC register is empty or read, any content in the buffer register is passed to the CC register. The
buffer valid flag is passed to set the CCx interrupt flag (IF) and generate the optional interrupt.
Figure 13-5. Capture double buffering.
Both the CCx and CCxBUF registers are available as an I/O register. This allows initialization
and bypassing of the buffer register and the double buffering function.
Depending on the mode of operation, the counter is cleared, reloaded, incremented, or decre-
mented at each timer/counter clock input.
In normal operation, the counter will count in the direction set by the direction (DIR) bit for each
clock until it reaches TOP or BOTTOM. When up-counting and TOP is reached, the counter will
be set to zero when the next clock is given. When down-counting, the counter is reloaded with
the period register value when BOTTOM is reached.
UPDATE
"capture"
"INT/DMA
request"
BV
IF
BV
EN
EN
"write enable"
CCxBUF
data read
EN
EN
CCx
CNT
CNT
Atmel AVR XMEGA B
"data write"
CCxBUF
=
CCx
"match"
Figure
13-5.
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