AT90PWM81 Atmel Corporation, AT90PWM81 Datasheet - Page 94
![no-image](/images/manufacturer_photos/0/0/79/atmel_corporation_sml.jpg)
AT90PWM81
Manufacturer Part Number
AT90PWM81
Description
Manufacturer
Atmel Corporation
Datasheet
1.AT90PWM161.pdf
(325 pages)
Specifications of AT90PWM81
Flash (kbytes)
8 Kbytes
Pin Count
20
Max. Operating Frequency
16 MHz
Cpu
8-bit AVR
Hardware Qtouch Acquisition
No
Max I/o Pins
20
Ext Interrupts
3
Usb Speed
No
Usb Interface
No
Spi
1
Graphic Lcd
No
Video Decoder
No
Camera Interface
No
Adc Channels
11
Adc Resolution (bits)
10
Adc Speed (ksps)
125
Analog Comparators
3
Resistive Touch Screen
No
Dac Channels
1
Dac Resolution (bits)
10
Temp. Sensor
Yes
Crypto Engine
No
Sram (kbytes)
0.25
Eeprom (bytes)
512
Self Program Memory
YES
Dram Memory
No
Nand Interface
No
Picopower
No
Temp. Range (deg C)
-40 to 125
I/o Supply Class
2.7 to 5.5
Operating Voltage (vcc)
2.7 to 5.5
Fpu
No
Mpu / Mmu
no / no
Timers
1
Output Compare Channels
8
Input Capture Channels
1
Pwm Channels
6
32khz Rtc
No
Calibrated Rc Oscillator
Yes
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
AT90PWM81-16MF
Manufacturer:
Atmel
Quantity:
3 118
Company:
Part Number:
AT90PWM81-16MN
Manufacturer:
Atmel
Quantity:
2 446
Company:
Part Number:
AT90PWM81-16SF
Manufacturer:
Atmel
Quantity:
2 428
Company:
Part Number:
AT90PWM81-16SN
Manufacturer:
Atmel
Quantity:
1 500
- Current page: 94 of 325
- Download datasheet (6Mb)
11.6.2
11.7
94
Timer/Counter Timing Diagrams
AT90PWM81
Clear Timer on Compare Match (CTC) Mode
not cleared. However, combined with the timer overflow interrupt that automatically clears the TOV1
Flag, the timer resolution can be increased by software. There are no special cases to consider in the Nor-
mal mode, a new counter value can be written anytime.
The Input Capture unit is easy to use in Normal mode. However, observe that the maximum interval
between the external events must not exceed the resolution of the counter. If the interval between events
are too long, the timer overflow interrupt must be used to extend the resolution for the capture unit.
In Clear Timer on Compare or CTC mode (WGM13 = 1, previous mode 12), the ICR1 Register are used
to manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter value
(TCNT1) matches the ICR1 . The ICR1 define the top value for the counter, hence also its resolution. This
mode allows greater control of the compare match output frequency. It also simplifies the operation of
counting external events.
The timing diagram for the CTC mode is shown in
until a compare match occurs with ICR1, and then counter (TCNT1) is cleared.
Figure 11-5.
An interrupt can be generated at each time the counter value reaches the TOP value by using the ICF1
Flag . If the interrupt is enabled, the interrupt handler routine can be used for updating the TOP value.
However, changing the TOP to a value close to BOTTOM when the counter is running with none or a low
prescaler value must be done with care since the CTC mode does not have the double buffering feature. If
the new value written to ICR1 is lower than the current value of TCNT1, the counter will miss the com-
pare match. The counter will then have to count to its maximum value (0xFFFF) and wrap around starting
at 0x0000 before the compare match can occur. In many cases this feature is not desirable.
As for the Normal mode of operation, the TOV1 Flag is set in the same timer clock cycle that the counter
counts from MAX to 0x0000.
The Timer/Counter is a synchronous design and the timer clock (clk
enable signal in the following figures. The figures include information on when Interrupt Flags are set.
Figure 11-6
TCNTn
shows the count sequence close to TOP in various modes.
CTC Mode, Timing Diagram
Figure
11-5. The counter value (TCNT1) increases
T1
) is therefore shown as a clock
(Interrupt on TOP)
ICFn Interrupt Flag Set
7734P–AVR–08/10
Related parts for AT90PWM81
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![U641B](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:
![U4082B](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet:
![U4089B](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
MONOLITHIC INTEGRATED FEATUREPHONE CIRCUIT
Manufacturer:
ATMEL Corporation
Datasheet:
![U4255BM-M](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
AM-FM Receiver IC U4255BM-M
Manufacturer:
ATMEL Corporation
Datasheet:
![U4089B-P](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Monolithic Integrated Feature Phone Circuit
Manufacturer:
ATMEL Corporation
Datasheet:
![TDA4470](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Multistandard Video-IF and Quasi Parallel Sound Processing
Manufacturer:
ATMEL Corporation
Datasheet:
![ATF22V10B-25PC](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
High-performance EE PLD
Manufacturer:
ATMEL Corporation
Datasheet:
![AT89C51ED2-IM](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
8-bit Flash Microcontroller
Manufacturer:
ATMEL Corporation
Datasheet:
![AT24C01](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
2-Wire Serial EEPROM
Manufacturer:
ATMEL Corporation
Datasheet:
![U6046B](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
U6046BREAR WINDOW HEATING TIMER / LONG-TERM TIMER
Manufacturer:
ATMEL Corporation
Datasheet: