ATMEGA3250-16AUR Atmel, ATMEGA3250-16AUR Datasheet - Page 98

• Manufacturer Part Number: ATMEGA3250-16AUR
• Description: MCU AVR 32K FLASH 16MHZ 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA3250-16AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K 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: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

14.9.2
14.9.3
2570M–AVR–04/11
TCNT0 – Timer/Counter Register
OCR0A – Output Compare Register A
Table 14-5.
Note:
• Bit 2:0 – CS02:0: Clock Select
The three Clock Select bits select the clock source to be used by the Timer/Counter.
Table 14-6.
If external pin modes are used for the Timer/Counter0, transitions on the T0 pin will clock the
counter even if the pin is configured as an output. This feature allows software control of the
counting.
The Timer/Counter Register gives direct access, both for read and write operations, to the
Timer/Counter unit 8-bit counter. Writing to the TCNT0 Register blocks (removes) the compare
match on the following timer clock. Modifying the counter (TCNT0) while the counter is running,
introduces a risk of missing a compare match between TCNT0 and the OCR0A Register.
Bit
0x26 (0x46)
Read/Write
Initial Value
Bit
0x27 (0x47)
Read/Write
Initial Value
CS02
COM0A1
0
0
0
0
1
1
1
1
0
0
1
1
1. A special case occurs when OCR0A equals TOP and COM0A1 is set. In this case, the com-
CS01
pare match is ignored, but the set or clear is done at TOP. See
page 93
0
0
1
1
0
0
1
1
Compare Output Mode, Phase Correct PWM Mode
Clock Select Bit Description
R/W
R/W
COM0A0
7
0
7
0
CS00
0
1
0
1
for more details.
0
1
0
1
0
1
0
1
R/W
R/W
6
0
6
0
Description
No clock source (Timer/Counter stopped)
clk
clk
clk
clk
clk
External clock source on T0 pin. Clock on falling edge.
External clock source on T0 pin. Clock on rising edge.
Description
Normal port operation, OC0A disconnected.
Reserved
Clear OC0A on compare match when up-counting. Set OC0A on
compare match when counting down.
Set OC0A on compare match when up-counting. Clear OC0A on
compare match when counting down.
I/O
I/O
I/O
I/O
I/O
/(No prescaling)
/8 (From prescaler)
/64 (From prescaler)
/256 (From prescaler)
/1024 (From prescaler)
R/W
R/W
5
0
5
0
R/W
R/W
4
0
4
0
OCR0A[7:0]
TCNT0[7:0]
ATmega325/3250/645/6450
R/W
R/W
3
0
3
0
R/W
R/W
2
0
2
0
R/W
R/W
1
0
1
0
(1)
“Phase Correct PWM Mode” on
R/W
R/W
0
0
0
0
TCNT0
OCR0
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