ATMEGA640-16CU Atmel, ATMEGA640-16CU Datasheet - Page 184

• Manufacturer Part Number: ATMEGA640-16CU
• Description: IC MCU AVR 64K FLASH 100-CBGA
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA640-16CU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 86
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TFBGA
• Processor Series: ATMEGA64x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 8 KB
• Interface Type: 2-Wire, SPI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 86
• Number Of Timers: 6
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 16 Channel
• For Use With: ATSTK600-TQFP100 - STK600 SOCKET/ADAPTER 100-TQFP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRISP2 - PROGRAMMER AVR IN SYSTEMATSTK503 - STARTER KIT AVR EXP MODULE 100P
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.8
2549M–AVR–09/10
Asynchronous Operation of Timer/Counter2
Figure 19-10
Figure 19-10. Timer/Counter Timing Diagram, Setting of OCF2A, with Prescaler (f
Figure 19-11
Figure 19-11. Timer/Counter Timing Diagram, Clear Timer on Compare Match mode, with Pres-
When Timer/Counter2 operates asynchronously, some considerations must be taken.
•
Warning: When switching between asynchronous and synchronous clocking of
Timer/Counter2, the Timer Registers TCNT2, OCR2x, and TCCR2x might be corrupted. A
safe procedure for switching clock source is:
1. Disable the Timer/Counter2 interrupts by clearing OCIE2x and TOIE2.
2. Select clock source by setting AS2 as appropriate.
3. Write new values to TCNT2, OCR2x, and TCCR2x.
4. To switch to asynchronous operation: Wait for TCN2UB, OCR2xUB, and TCR2xUB.
5. Clear the Timer/Counter2 Interrupt Flags.
6. Enable interrupts, if needed.
TCNTn
TCNTn
(clk
(clk
OCRnx
(CTC)
OCRnx
OCFnx
OCFnx
clk
clk
clk
clk
I/O
I/O
I/O
I/O
Tn
Tn
/8)
/8)
shows the setting of OCF2A in all modes except CTC mode.
shows the setting of OCF2A and the clearing of TCNT2 in CTC mode.
caler (f
clk_I/O
OCRnx - 1
TOP - 1
/8)
ATmega640/1280/1281/2560/2561
TOP
OCRnx
OCRnx Value
TOP
BOTTOM
OCRnx + 1
BOTTOM + 1
OCRnx + 2
clk_I/O
/8)
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