ATmega64 Atmel Corporation, ATmega64 Datasheet - Page 106

• Manufacturer Part Number: ATmega64
• Manufacturer: Atmel Corporation

Specifications of ATmega64

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 8
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• 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): 4
• Eeprom (bytes): 2048
• 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: 4
• Output Compare Channels: 8
• Input Capture Channels: 2
• Pwm Channels: 7
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

TCNT0 –
Timer/Counter
Register
OCR0 – Output
Compare Register
2490Q–AVR–06/10
• Bit 2:0 – CS02:0: Clock Select
The three Clock Select bits select the clock source to be used by the Timer/Counter, see
56.
Table 56. Clock Select Bit Description
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.
The Output Compare Register contains an 8-bit value that is continuously compared with the
counter value (TCNT0). A match can be used to generate an Output Compare interrupt, or to
generate a waveform output on the OC0 pin.
Bit
0x32 (0x52)
Read/Write
Initial Value
Bit
0x31 (0x51)
Read/Write
Initial Value
CS02
0
0
0
0
1
1
1
1
CS01
R/W
R/W
0
0
1
1
0
0
1
1
7
0
7
0
R/W
R/W
6
0
6
0
CS00
0
1
0
1
0
1
0
1
R/W
R/W
5
0
5
0
Description
No clock source (Timer/counter stopped)
clk
clk
clk
clk
clk
clk
clk
T0S
T0S
T0S
T0S
T0S
T
T
0
0
S
S
/256 (From prescaler)
/1024 (From prescaler)
/(No prescaling)
/8 (From prescaler)
/32 (From prescaler)
/64 (From prescaler)
/128 (From prescaler)
R/W
R/W
4
0
4
0
TCNT0[7:0]
OCR0[7:0]
R/W
R/W
3
0
3
0
R/W
R/W
2
0
2
0
R/W
R/W
1
0
1
0
ATmega64(L)
R/W
R/W
0
0
0
0
TCNT0
OCR0
Table
106