ATxmega128B1 Atmel Corporation, ATxmega128B1 Datasheet - Page 159

• 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

13.7.3
8291A–AVR–10/11
Pulse Width Capture
timer/counter restart until the event occurred. This can be used to calculate the frequency (f) of
the signal:
Figure 13-12 on page 159
twice.
Figure 13-12. Frequency capture of an external signal.
Since all capture channels use the same counter (CNT), only one capture channel must be
enabled at a time. If two capture channels are used with different sources, the counter will be
restarted on positive edge events from both input sources, and the result will have no meaning.
Selecting the pulse width measure event action makes the enabled compare channel perform
the input capture action on falling edge events and the restart action on rising edge events. The
counter will then restart on positive edge events, and the input capture will be performed on the
negative edge event. The event source must be an I/O pin, and the sense configuration for the
pin must be set to generate an event on both edges.
example where the pulse width is measured twice for an external signal.
f
=
external signal
events
CNT
1
-- -
T
BOTTOM
MAX
shows an example where the period of an external signal is measured
Period (T)
Atmel AVR XMEGA B
Figure 13-13 on page 160
"capture"
shows and
159