ATMEGA2560V-8AU Atmel, ATMEGA2560V-8AU Datasheet - Page 151

• Manufacturer Part Number: ATMEGA2560V-8AU
• Description: IC AVR MCU 256K 8MHZ 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA2560V-8AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 86
• Program Memory Size: 256KB (128K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TQFP, 100-VQFP
• Processor Series: ATMEGA256x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 8 KB
• Interface Type: 2-Wire, SPI, USART
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 86
• Number Of Timers: 6
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 16 Channel
• A/d Inputs: 16-Channel, 10-Bit
• Cpu Speed: 8 MIPS
• Eeprom Memory: 4K Bytes
• Input Output: 86
• Interface: 2-Wire/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 100-pin TQFP
• Programmable Memory: 256K Bytes
• Timers: 2-8-bit, 4-16-bit
• Voltage, Range: 1.8-5.5 V
• Package: 100TQFP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 8 MHz
• For Use With: ATSTK600-TQFP100 - STK600 SOCKET/ADAPTER 100-TQFP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPIATAVRISP2 - PROGRAMMER AVR IN SYSTEMATSTK503 - STARTER KIT AVR EXP MODULE 100PATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2549M–AVR–09/10
Figure 16-7. Fast PWM Mode, Timing Diagram
The Timer/Counter Overflow Flag (TOVn) is set each time the counter reaches TOP. In addition
the OCnA or ICFn Flag is set at the same timer clock cycle as TOVn is set when either OCRnA
or ICRn is used for defining the TOP value. If one of the interrupts are enabled, the interrupt han-
dler routine can be used for updating the TOP and compare values.
When changing the TOP value the program must ensure that the new TOP value is higher or
equal to the value of all of the Compare Registers. If the TOP value is lower than any of the
Compare Registers, a compare match will never occur between the TCNTn and the OCRnx.
Note that when using fixed TOP values the unused bits are masked to zero when any of the
OCRnx Registers are written.
The procedure for updating ICRn differs from updating OCRnA when used for defining the TOP
value. The ICRn Register is not double buffered. This means that if ICRn is changed to a low
value when the counter is running with none or a low prescaler value, there is a risk that the new
ICRn value written is lower than the current value of TCNTn. The result will then be that the
counter will miss the compare match at the TOP value. The counter will then have to count to the
MAX value (0xFFFF) and wrap around starting at 0x0000 before the compare match can occur.
The OCRnA Register however, is double buffered. This feature allows the OCRnA I/O location
to be written anytime. When the OCRnA I/O location is written the value written will be put into
the OCRnA Buffer Register. The OCRnA Compare Register will then be updated with the value
in the Buffer Register at the next timer clock cycle the TCNTn matches TOP. The update is done
at the same timer clock cycle as the TCNTn is cleared and the TOVn Flag is set.
Using the ICRn Register for defining TOP works well when using fixed TOP values. By using
ICRn, the OCRnA Register is free to be used for generating a PWM output on OCnA. However,
if the base PWM frequency is actively changed (by changing the TOP value), using the OCRnA
as TOP is clearly a better choice due to its double buffer feature.
In fast PWM mode, the compare units allow generation of PWM waveforms on the OCnx pins.
Setting the COMnx1:0 bits to two will produce a non-inverted PWM and an inverted PWM output
can be generated by setting the COMnx1:0 to three (see
value will only be visible on the port pin if the data direction for the port pin is set as output
(DDR_OCnx). The PWM waveform is generated by setting (or clearing) the OCnx Register at
the compare match between OCRnx and TCNTn, and clearing (or setting) the OCnx Register at
the timer clock cycle the counter is cleared (changes from TOP to BOTTOM).
TCNTn
OCnx
OCnx
Period
1
2
ATmega640/1280/1281/2560/2561
3
4
5
6
7
Table on page
8
(COMnx1:0 = 2)
(COMnx1:0 = 3)
OCRnx / TOP Update
and TOVn Interrupt Flag
Set and OCnA Interrupt
Flag Set or ICFn
Interrupt Flag Set
(Interrupt on TOP)
159). The actual OCnx
151