ATXMEGA256A3B-MH Atmel, ATXMEGA256A3B-MH Datasheet - Page 158

• Manufacturer Part Number: ATXMEGA256A3B-MH
• Description: MCU AVR 256KB FLASH A3B 64-QFN
• Manufacturer: Atmel
• Series: AVR® XMEGAr

Specifications of ATXMEGA256A3B-MH

• Core Processor: AVR
• Core Size: 8/16-Bit
• Speed: 32MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 49
• Program Memory Size: 256KB (128K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 1.6 V ~ 3.6 V
• Data Converters: A/D 16x12b; D/A 2x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-MLF®, 64-QFN
• Processor Series: ATXMEGA256x
• Core: AVR8
• Data Bus Width: 8 bit, 16 bit
• Data Ram Size: 16 KB
• Interface Type: I2C, SPI, USART
• Maximum Clock Frequency: 32 MHz
• Number Of Programmable I/os: 49
• Number Of Timers: 7
• Operating Supply Voltage: 1.6 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12 bit, 8 Channel
• On-chip Dac: 12 bit, 2 Channel
• For Use With: ATAVRONEKIT - KIT AVR/AVR32 DEBUGGER/PROGRMMRATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPI
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ATXMEGA256A3B-MU; ATXMEGA256A3B-MU

14.7.2
14.7.3
8077H–AVR–12/09
Frequency Capture
Pulse-width Capture
Selecting the frequency capture event action, makes the enabled capture channel perform an
input capture and restart on positive edge events. 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 previous Timer/Counter restart and until the event occurred. This can be used to calculate
the frequency, f, of the signal:
Figure 14-10 on page 158
nal signal.
Figure 14-10. 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 14-11 on page 159
XMEGA A
shows and exam-
"capture"
158