ATMEGA644P-A15MZ Atmel, ATMEGA644P-A15MZ Datasheet - Page 132

• Manufacturer Part Number: ATMEGA644P-A15MZ
• Description: MCU AVR 64KB FLASH 16MHZ 44QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644P-A15MZ

• Package / Case: 44-VQFN Exposed Pad
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Speed: 16MHz
• Number Of I /o: 32
• Eeprom Size: 2K x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Program Memory Size: 64KB (64K x 8)
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: I²C, SPI, UART/USART
• Core Size: 8-Bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

132
ATmega164P/324P/644P
The COMnA1:0 and COMnB1:0 control the Output Compare pins (OCnA and OCnB respec-
tively) behavior. If one or both of the COMnA1:0 bits are written to one, the OCnA output
overrides the normal port functionality of the I/O pin it is connected to. If one or both of the
COMnB1:0 bit are written to one, the OCnB output overrides the normal port functionality of the
I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit correspond-
ing to the OCnA or OCnB pin must be set in order to enable the output driver.
When the OCnA or OCnB is connected to the pin, the function of the COMnx1:0 bits is depen-
dent of the WGMn3:0 bits setting.
when the WGMn3:0 bits are set to a Normal or a CTC mode (non-PWM).
Table 14-2.
Table 14-3 on page 132
the fast PWM mode.
Table 14-3.
Note:
COMnA1/COMnB1
COMnA1/COMnB1
1. A special case occurs when OCRnA/OCRnB equals TOP and COMnA1/COMnB1 is set. In
0
0
1
1
0
0
1
1
this case the compare match is ignored, but the set or clear is done at BOTTOM.
PWM Mode” on page 123.
Compare Output Mode, non-PWM
Compare Output Mode, Fast PWM
shows the COMnx1:0 bit functionality when the WGMn3:0 bits are set to
COMnA0/COMnB0
COMnA0/COMnB0
0
1
0
1
0
1
0
1
Table 14-2 on page 132
for more details.
Description
Normal port operation, OCnA/OCnB disconnected.
WGMn3:0 = 14 or 15: Toggle OC1A on Compare
Match, OC1B disconnected (normal port operation).
For all other WGM1 settings, normal port operation,
OC1A/OC1B disconnected.
Clear OCnA/OCnB on Compare Match, set
OCnA/OCnB at BOTTOM (non-inverting mode)
Set OCnA/OCnB on Compare Match, clear
OCnA/OCnB at BOTTOM (inverting mode)
Description
Normal port operation, OCnA/OCnB disconnected.
Toggle OCnA/OCnB on Compare Match.
Clear OCnA/OCnB on Compare Match (Set output to
low level).
Set OCnA/OCnB on Compare Match (Set output to
high level).
(1)
shows the COMnx1:0 bit functionality
7674F–AVR–09/09
See “Fast