ATmega32M1 Atmel Corporation, ATmega32M1 Datasheet - Page 94

• Manufacturer Part Number: ATmega32M1
• Manufacturer: Atmel Corporation

Specifications of ATmega32M1

• 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 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: 2
• Output Compare Channels: 14
• Input Capture Channels: 1
• Pwm Channels: 10
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

14.8
94
Timer/Counter Timing Diagrams
ATmega16M1/32M1/64M1
one allows the OC0A pin to toggle on Compare Matches if the WGM02 bit is set. This option is
not available for the OC0B pin (see
visible on the port pin if the data direction for the port pin is set as output. The PWM waveform is
generated by clearing (or setting) the OC0x Register at the compare match between OCR0x and
TCNT0 when the counter increments, and setting (or clearing) the OC0x Register at compare
match between OCR0x and TCNT0 when the counter decrements. The PWM frequency for the
output when using phase correct PWM can be calculated by the following equation:
The N variable represents the prescale factor (1, 8, 64, 256, or 1024).
The extreme values for the OCR0A Register represent special cases when generating a PWM
waveform output in the phase correct PWM mode. If the OCR0A is set equal to BOTTOM, the
output will be continuously low and if set equal to MAX the output will be continuously high for
non-inverted PWM mode. For inverted PWM the output will have the opposite logic values.
At the very start of period 2 in
even though there is no Compare Match. The point of this transition is to guarantee symmetry
around BOTTOM. There are two cases that give a transition without Compare Match.
The Timer/Counter is a synchronous design and the timer clock (clk
clock enable signal in the following figures. The figures include information on when interrupt
flags are set.
shows the count sequence close to the MAX value in all modes other than phase correct PWM
mode.
Figure 14-8. Timer/Counter Timing Diagram, no Prescaling
• OCRnx changes its value from MAX, like in
• The timer starts counting from a value higher than the one in OCRnx, and for that reason
is MAX the OCn pin value is the same as the result of a down-counting Compare Match. To
ensure symmetry around BOTTOM the OCnx value at MAX must correspond to the result of
an up-counting Compare Match
misses the Compare Match and hence the OCnx change that would have happened on the
way up
TCNTn
(clk
TOVn
clk
clk
I/O
I/O
Tn
/1)
Figure 14-8
MAX - 1
contains timing data for basic Timer/Counter operation. The figure
Figure 14-7 on page 93
Table 14-7 on page
f
OCnxPCPWM
MAX
Figure 14-7 on page
=
----------------- -
N 510
f
clk_I/O
⋅
OCnx has a transition from high to low
98). The actual OC0x value will only be
BOTTOM
93. When the OCR0A value
T0
) is therefore shown as a
BOTTOM + 1
8209D–AVR–11/10