ATmega640 Atmel Corporation, ATmega640 Datasheet - Page 172

• Manufacturer Part Number: ATmega640
• Manufacturer: Atmel Corporation

Specifications of ATmega640

• Flash (kbytes): 64 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 86
• Ext Interrupts: 32
• Usb Speed: No
• Usb Interface: No
• Spi: 5
• Twi (i2c): 1
• Uart: 4
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 16
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 8
• Eeprom (bytes): 4096
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 6
• Output Compare Channels: 16
• Input Capture Channels: 4
• Pwm Channels: 15
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

19. Output Compare Modulator (OCM1C0A)
19.1
19.2
2549N–AVR–05/11
Overview
Description
The Output Compare Modulator (OCM) allows generation of waveforms modulated with a carrier
frequency. The modulator uses the outputs from the Output Compare Unit C of the 16-bit
Timer/Counter1 and the Output Compare Unit of the 8-bit Timer/Counter0. For more details
about these Timer/Counters see
bit Timer/Counter2 with PWM and Asynchronous Operation” on page
Figure 19-1. Output Compare Modulator, Block Diagram
When the modulator is enabled, the two output compare channels are modulated together as
shown in the block diagram (see
The Output Compare unit 1C and Output Compare unit 2 shares the PB7 port pin for output. The
outputs of the Output Compare units (OC1C and OC0A) overrides the normal PORTB7 Register
when one of them is enabled (that is, when COMnx1:0 is not equal to zero). When both OC1C
and OC0A are enabled at the same time, the modulator is automatically enabled.
The functional equivalent schematic of the modulator is shown on
includes part of the Timer/Counter units and the port B pin 7 output driver circuit.
Figure 19-2. Output Compare Modulator, Schematic
( From Waveform Generator )
( From Waveform Generator )
COMA01
COMA00
COM1C1
COM1C0
Timer/Counter 1
Timer/Counter 0
PORTB7
D
OC1C
D
OC0A
D
Q
Q
Q
ATmega640/1280/1281/2560/2561
“Timer/Counter 0, 1, 3, 4, and 5 Prescaler” on page 169
Figure
DATABUS
19-1).
OC1C
OC0A
Modulator
0
1
DDRB7
D
Figure
Q
1
0
174.
OC0A / PB7
OC1C /
19-2. The schematic
Pin
Vcc
OC0A/ PB7
and
OC1C /
Pin
172
“8-