ATmega16 Atmel Corporation, ATmega16 Datasheet - Page 100

• Manufacturer Part Number: ATmega16
• Manufacturer: Atmel Corporation

Specifications of ATmega16

• 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

Compare Match
Output Unit
Compare Output Mode
and Waveform
Generation
2466T–AVR–07/10
The Compare Output mode (COM1x1:0) bits have two functions. The Waveform Generator uses
the COM1x1:0 bits for defining the Output Compare (OC1x) state at the next compare match.
Secondly the COM1x1:0 bits control the OC1x pin output source.
schematic of the logic affected by the COM1x1:0 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 COM1x1:0 bits are shown. When referring to the
OC1x state, the reference is for the internal OC1x Register, not the OC1x pin. If a System Reset
occur, the OC1x Register is reset to “0”.
Figure 44. Compare Match Output Unit, Schematic
The general I/O port function is overridden by the Output Compare (OC1x) from the Waveform
Generator if either of the COM1x1:0 bits are set. However, the OC1x pin direction (input or out-
put) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction
Register bit for the OC1x pin (DDR_OC1x) must be set as output before the OC1x value is visi-
ble on the pin. The port override function is generally independent of the Waveform Generation
mode, but there are some exceptions. Refer to
The design of the output compare pin logic allows initialization of the OC1x state before the out-
put is enabled. Note that some COM1x1:0 bit settings are reserved for certain modes of
operation.
The COM1x1:0 bits have no effect on the Input Capture unit.
The Waveform Generator uses the COM1x1:0 bits differently in normal, CTC, and PWM modes.
For all modes, setting the COM1x1:0 = 0 tells the Waveform Generator that no action on the
OC1x Register is to be performed on the next compare match. For compare output actions in the
non-PWM modes refer to
111, and for phase correct and phase and frequency correct PWM refer to
111.
A change of the COM1x1:0 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
FOC1x strobe bits.
See “16-bit Timer/Counter Register Description” on page 110.
COMnx1
COMnx0
FOCnx
clk
I/O
Table 44 on page
Waveform
Generator
D
D
D
PORT
DDR
OCnx
110. For fast PWM mode refer to
Table
Q
Q
Q
44,
Table 45
1
0
Figure 44
and
ATmega16(L)
Table 46
shows a simplified
OCnx
Pin
Table 46 on page
Table 45 on page
for details.
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