ATxmega16D4 Atmel Corporation, ATxmega16D4 Datasheet - Page 130

• Manufacturer Part Number: ATxmega16D4
• Manufacturer: Atmel Corporation

Specifications of ATxmega16D4

• Flash (kbytes): 16 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 34
• Ext Interrupts: 34
• Usb Speed: No
• Usb Interface: No
• Spi: 4
• Twi (i2c): 2
• Uart: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 12
• Adc Speed (ksps): 200
• Analog Comparators: 2
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 2
• Eeprom (bytes): 1024
• 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: 4
• Output Compare Channels: 14
• Input Capture Channels: 14
• Pwm Channels: 14
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

12.7.2
12.7.3
8210B–AVR–04/10
Frequency Capture
Pulse-width Capture
Selecting the frequency capture event action, makes the enabled capture channel perform a
input capture and restart on any event. This enables Timer/Counter to use capture to measure
the period or frequency of a signal directly. The capture result will be the time, T, from the previ-
ous Timer/Counter restart and until the event occurred. This can be used to calculate the
frequency, f, of the signal:
Figure 12-10 on page 130
nal signal.
Figure 12-10. Frequency capture of an external signal
Since all capture channels uses the same Counter (CNT), only one capture channels must be
enabled at a time. If two capture channels are used with different source, the Counter will be
restarted on positive edge events from both input sources, and the result from the input capture
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 start at zero at every start of a pulse and the input capture will be performed at
the end of the pulse. The event source must be an I/O pin and the sense configuration for the pin
must be set up to generate an event on both edges.
ple where the pulse width is measured twice for an external signal.
f
=
external signal
events
CNT
1
-- -
T
MAX
BOT
shows an example where the Period is measured twice for an exter-
Period (T)
Figure 12-11 on page 131
XMEGA D
shows and exam-
"capture"
130