ATmega16A Atmel Corporation, ATmega16A Datasheet - Page 84

• Manufacturer Part Number: ATmega16A
• Manufacturer: Atmel Corporation

Specifications of ATmega16A

• Flash (kbytes): 16 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 3
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

14.9.2
84
ATmega16A
TCNT0 – Timer/Counter Register
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 OCR0 Register.
Bit
Read/Write
Initial Value
COM01
CS02
0
0
0
0
1
1
1
1
0
0
1
1
1. A special case occurs when OCR0 equals TOP and COM01 is set. In this case, the compare
match is ignored, but the set or clear is done at TOP. See
78
COM00
CS01
for more details.
0
0
1
1
0
0
1
1
Compare Output Mode, Phase Correct PWM Mode
Clock Select Bit Description
0
1
0
1
R/W
7
0
CS00
Description
Normal port operation, OC0 disconnected.
Reserved
Clear OC0 on compare match when up-counting. Set OC0 on compare match
when downcounting.
Set OC0 on compare match when up-counting. Clear OC0 on compare match
when downcounting.
0
1
0
1
0
1
0
1
R/W
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.
I/O
I/O
I/O
I/O
I/O
R/W
5
0
/(No prescaling)
/8 (From prescaler)
/64 (From prescaler)
/256 (From prescaler)
/1024 (From prescaler)
R/W
4
0
TCNT0[7:0]
R/W
3
0
R/W
“Phase Correct PWM Mode” on page
2
0
(1)
R/W
1
0
R/W
0
0
8154B–AVR–07/09
TCNT0