ATmega64 Atmel Corporation, ATmega64 Datasheet - Page 97

• 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

Compare Match
Output Unit
Compare Output Mode
and Waveform
Generation
2490Q–AVR–06/10
The Compare Output mode (COM01:0) bits have two functions. The Waveform Generator uses
the COM01:0 bits for defining the Output Compare (OC0) state at the next Compare Match.
Also, the COM01:0 bits control the OC0 pin output source.
matic of the logic affected by the COM01:0 bit setting. The I/O Registers, I/O bits, and I/O pins in
the figure are shown in bold. Only the parts of the general I/O port control registers (DDR and
PORT) that are affected by the COM01:0 bits are shown. When referring to the OC0 state, the
reference is for the internal OC0 Register, not the OC0 pin.
Figure 37. Compare Match Output Unit, Schematic
The general I/O port function is overridden by the Output Compare (OC0) from the Waveform
Generator if either of the COM01:0 bits are set. However, the OC0 pin direction (input or output)
is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction Regis-
ter bit for the OC0 pin (DDR_OC0) must be set as output before the OC0 value is visible on the
pin. The port override function is independent of the Waveform Generation mode.
The design of the Output Compare pin logic allows initialization of the OC0 state before the out-
put is enabled. Note that some COM01:0 bit settings are reserved for certain modes of
operation.
The Waveform Generator uses the COM01:0 bits differently in Normal, CTC, and PWM modes.
For all modes, setting the COM01:0 = 0 tells the Waveform Generator that no action on the OC0
Register is to be performed on the next Compare Match. For compare output actions in the non-
PWM modes refer to
and for phase correct PWM refer to
A change of the COM01:0 bits state will have effect at the first Compare Match after the bits are
written. For non-PWM modes, the action can be forced to have immediate effect by using the
FOC0 strobe bits.
COMn1
COMn0
FOCn
clk
I/O
See “8-bit Timer/Counter Register Description” on page 104.
Table 53 on page
Waveform
Generator
Table 55 on page
105. For fast PWM mode, refer to
D
D
D
PORT
DDR
OCn
105.
Q
Q
Q
Figure 37
1
0
ATmega64(L)
shows a simplified sche-
Table 54 on page
OCn
Pin
105,
97