ATmega32C1 Automotive Atmel Corporation, ATmega32C1 Automotive Datasheet - Page 127

• Manufacturer Part Number: ATmega32C1 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega32C1 Automotive

• Flash (kbytes): 32 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 27
• Ext Interrupts: 27
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Uart: 1
• Can: 1
• Lin: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 125
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 1
• Dac Resolution (bits): 10
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 150
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

7647G–AVR–09/11
As
rical in all periods. Since the OCRnx Registers are updated at BOTTOM, the length of the
rising and the falling slopes will always be equal. This gives symmetrical output pulses and is
therefore frequency correct.
Using the ICRn Register for defining TOP works well when using fixed TOP values. By using
ICRn, the OCRnA Register is free to be used for generating a PWM output on OCnA. How-
ever, if the base PWM frequency is actively changed by changing the TOP value, using the
OCRnA as TOP is clearly a better choice due to its double buffer feature.
In phase and frequency correct PWM mode, the compare units allow generation of PWM
waveforms on the OCnx pins. Setting the COMnx1:0 bits to two will produce a non-inverted
PWM and an inverted PWM output can be generated by setting the COMnx1:0 to three (See
Table on page
direction for the port pin is set as output (DDR_OCnx). The PWM waveform is generated by
setting (or clearing) the OCnx Register at the compare match between OCRnx and TCNTn
when the counter increments, and clearing (or setting) the OCnx Register at compare match
between OCRnx and TCNTn when the counter decrements. The PWM frequency for the out-
put when using phase and frequency correct PWM can be calculated by the following
equation:
The N variable represents the prescaler divider (1, 8, 64, 256, or 1024).
The extreme values for the OCRnx Register represents special cases when generating a
PWM waveform output in the phase correct PWM mode. If the OCRnx is set equal to BOT-
TOM the output will be continuously low and if set equal to TOP the output will be set to high
for non-inverted PWM mode. For inverted PWM the output will have the opposite logic values.
If OCR1A is used to define the TOP value (WGM13:0 = 9) and COM1A1:0 = 1, the OC1A out-
put will toggle with a 50% duty cycle.
f
OCnxPFCPWM
Figure 13-9
=
shows the output generated is, in contrast to the phase correct mode, symmet-
131). The actual OCnx value will only be visible on the port pin if the data
---------------------------------
2
f
clk_I/O
N
TOP
Atmel ATmega16/32/64/M1/C1
127