AT90PWM216-16SE ATMEL [ATMEL Corporation], AT90PWM216-16SE Datasheet - Page 111
AT90PWM216-16SE
Manufacturer Part Number
AT90PWM216-16SE
Description
8-bit Microcontroller with 16K Bytes In-System Programmable flash
Manufacturer
ATMEL [ATMEL Corporation]
Datasheet
1.AT90PWM216-16SE.pdf
(360 pages)
- Current page: 111 of 360
- Download datasheet (6Mb)
15.5.1
15.5.2
15.5.3
7710D–AVR–08/09
Input Capture Trigger Source
Noise Canceler
Using the Input Capture Unit
tion mode (WGMn3:0) bits must be set before the TOP value can be written to the ICRn
Register. When writing the ICRn Register the high byte must be written to the ICRnH I/O location
before the low byte is written to ICRnL.
For more information on how to access the 16-bit registers refer to
on page
The trigger sources for the Input Capture unit arethe Input Capture pin (ICP1A & ICP1B).
Be aware that changing trigger source can trigger a capture. The Input Capture Flag must there-
fore be cleared after the change.
The Input Capture pin (ICPn) IS sampled using the same technique as for the Tn pin
1 on page
enabled, additional logic is inserted before the edge detector, which increases the delay by four
system clock cycles. Note that the input of the noise canceler and edge detector is always
enabled unless the Timer/Counter is set in a Waveform Generation mode that uses ICRn to
define TOP.
An Input Capture can be triggered by software by controlling the port of the ICPn pin.
The noise canceler improves noise immunity by using a simple digital filtering scheme. The
noise canceler input is monitored over four samples, and all four must be equal for changing the
output that in turn is used by the edge detector.
The noise canceler is enabled by setting the Input Capture Noise Canceler (ICNCn) bit in
Timer/Counter Control Register B (TCCRnB). When enabled the noise canceler introduces addi-
tional four system clock cycles of delay from a change applied to the input, to the update of the
ICRn Register. The noise canceler uses the system clock and is therefore not affected by the
prescaler.
The main challenge when using the Input Capture unit is to assign enough processor capacity
for handling the incoming events. The time between two events is critical. If the processor has
not read the captured value in the ICRn Register before the next event occurs, the ICRn will be
overwritten with a new value. In this case the result of the capture will be incorrect.
When using the Input Capture interrupt, the ICRn Register should be read as early in the inter-
rupt handler routine as possible. Even though the Input Capture interrupt has relatively high
priority, the maximum interrupt response time is dependent on the maximum number of clock
cycles it takes to handle any of the other interrupt requests.
Using the Input Capture unit in any mode of operation when the TOP value (resolution) is
actively changed during operation, is not recommended.
Measurement of an external signal’s duty cycle requires that the trigger edge is changed after
each capture. Changing the edge sensing must be done as early as possible after the ICRn
Register has been read. After a change of the edge, the Input Capture Flag (ICFn) must be
cleared by software (writing a logical one to the I/O bit location). For measuring frequency only,
the clearing of the ICFn Flag is not required (if an interrupt handler is used).
105.
82). The edge detector is also identical. However, when the noise canceler is
AT90PWM216/316
“Accessing 16-bit Registers”
(Figure 13-
111
Related parts for AT90PWM216-16SE
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
At90pwm2 8-bit Avr Microcontroller With 8k Bytes In-system Programmable Flash
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Atmel CryptoMemory
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
Atmel CryptoMemory
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
Atmel CryptoMemory, 16Kbit
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontrollers
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontroller with 16/32/64/128K Bytes In-System Programmable Flash
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
MONOLITHIC INTEGRATED FEATUREPHONE CIRCUIT
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
AM-FM Receiver IC U4255BM-M
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Monolithic Integrated Feature Phone Circuit
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Multistandard Video-IF and Quasi Parallel Sound Processing
Manufacturer:
ATMEL Corporation
Datasheet: