ATMEGA644P-20PQ Atmel, ATMEGA644P-20PQ Datasheet - Page 134

• Manufacturer Part Number: ATMEGA644P-20PQ
• Description: MCU AVR 64K FLASH 20MHZ 40-PDIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644P-20PQ

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 13-5.
Note:
13.11.2
8011O–AVR–07/10
Mode
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9
1. The CTCn and PWMn1:0 bit definition names are obsolete. Use the
WGMn3
TCCR1B – Timer/Counter1 Control Register B
location of these bits are compatible with previous versions of the timer.
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Waveform Generation Mode Bit Description
WGMn2
(CTCn)
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
• Bit 7 – ICNCn: Input Capture Noise Canceler
Setting this bit (to one) activates the Input Capture Noise Canceler. When the noise canceler is
activated, the input from the Input Capture pin (ICPn) is filtered. The filter function requires four
successive equal valued samples of the ICPn pin for changing its output. The Input Capture is
therefore delayed by four Oscillator cycles when the noise canceler is enabled.
• Bit 6 – ICESn: Input Capture Edge Select
This bit selects which edge on the Input Capture pin (ICPn) that is used to trigger a capture
event. When the ICESn bit is written to zero, a falling (negative) edge is used as trigger, and
when the ICESn bit is written to one, a rising (positive) edge will trigger the capture.
When a capture is triggered according to the ICESn setting, the counter value is copied into the
Input Capture Register (ICRn). The event will also set the Input Capture Flag (ICFn), and this
can be used to cause an Input Capture Interrupt, if this interrupt is enabled.
Bit
(0x81)
Read/Write
Initial Value
(PWMn1)
WGMn1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
ICNC1
R/W
7
0
(PWMn0)
WGMn0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
ICES1
R/W
6
0
Timer/Counter Mode of
Operation
Normal
PWM, Phase Correct, 8-bit
PWM, Phase Correct, 9-bit
PWM, Phase Correct, 10-bit
CTC
Fast PWM, 8-bit
Fast PWM, 9-bit
Fast PWM, 10-bit
PWM, Phase and Frequency
Correct
PWM, Phase and Frequency
Correct
PWM, Phase Correct
PWM, Phase Correct
CTC
(Reserved)
Fast PWM
Fast PWM
(1)
R
5
–
0
WGM13
R/W
4
0
WGM
ATmega164P/324P/644P
WGM12
n2:0 definitions. However, the functionality and
R/W
3
0
TOP
0xFFFF
0x00FF
0x01FF
0x03FF
OCRnA
0x00FF
0x01FF
0x03FF
ICRn
OCRnA
ICRn
OCRnA
ICRn
–
ICRn
OCRnA
CS12
R/W
2
0
CS11
R/W
Update of
OCRn
Immediate
TOP
TOP
TOP
Immediate
BOTTOM
BOTTOM
BOTTOM
BOTTOM
BOTTOM
TOP
TOP
Immediate
–
BOTTOM
BOTTOM
1
0
x
at
CS10
R/W
0
0
TOVn Flag
Set on
MAX
BOTTOM
BOTTOM
BOTTOM
MAX
TOP
TOP
TOP
BOTTOM
BOTTOM
BOTTOM
BOTTOM
MAX
–
TOP
TOP
TCCR1B
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