A000047 Arduino, A000047 Datasheet - Page 145

• Manufacturer Part Number: A000047
• Description: MCU, MPU & DSP Development Tools Mega2560
• Manufacturer: Arduino
• Series: -r
• Type: MCUr

Specifications of A000047

• Processor To Be Evaluated: ATmega2560
• Interface Type: USB, I2C, SPI
• Dimensions: 4 in x 2.1 in
• Operating Supply Voltage: 5 V
• Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: ATmega2560

16.7
2549M–AVR–09/10
Output Compare Units
Register has been read. After a change of the edge, the Input Capture Flag (ICFn) must be
cleared by software (writing a logical one to the I/O bit location). For measuring frequency only,
the clearing of the ICFn Flag is not required (if an interrupt handler is used).
The 16-bit comparator continuously compares TCNTn with the Output Compare Register
(OCRnx). If TCNT equals OCRnx the comparator signals a match. A match will set the Output
Compare Flag (OCFnx) at the next timer clock cycle. If enabled (OCIEnx = 1), the Output Com-
pare Flag generates an Output Compare interrupt. The OCFnx Flag is automatically cleared
when the interrupt is executed. Alternatively the OCFnx Flag can be cleared by software by writ-
ing a logical one to its I/O bit location. The Waveform Generator uses the match signal to
generate an output according to operating mode set by the Waveform Generation mode
(WGMn3:0) bits and Compare Output mode (COMnx1:0) bits. The TOP and BOTTOM signals
are used by the Waveform Generator for handling the special cases of the extreme values in
some modes of operation.
A special feature of Output Compare unit A allows it to define the Timer/Counter TOP value (that
is, counter resolution). In addition to the counter resolution, the TOP value defines the period
time for waveforms generated by the Waveform Generator.
Figure 16-4
bit names indicates the device number (n = n for Timer/Counter n), and the “x” indicates Output
Compare unit (A/B/C). The elements of the block diagram that are not directly a part of the Out-
put Compare unit are gray shaded.
Figure 16-4. Output Compare Unit, Block Diagram
shows a block diagram of the Output Compare unit. The small “n” in the register and
OCRnxH Buf. (8-bit)
OCRnxH (8-bit)
See “Modes of Operation” on page 148.
BOTTOM
OCRnx Buffer (16-bit Register)
TEMP (8-bit)
TOP
OCRnx (16-bit Register)
ATmega640/1280/1281/2560/2561
OCRnxL Buf. (8-bit)
OCRnxL (8-bit)
DATA BUS
Waveform Generator
WGMn3:0
=
(16-bit Comparator )
(8-bit)
COMnx1:0
TCNTnH (8-bit)
OCFnx (Int.Req.)
TCNTn (16-bit Counter)
TCNTnL (8-bit)
OCnx
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