AT90PWM2B-16SE ATMEL [ATMEL Corporation], AT90PWM2B-16SE Datasheet - Page 111
AT90PWM2B-16SE
Manufacturer Part Number
AT90PWM2B-16SE
Description
8-bit Microcontroller with 8K Bytes In-System Programmable Flash
Manufacturer
ATMEL [ATMEL Corporation]
Datasheet
1.AT90PWM2B-16SE.pdf
(361 pages)
- Current page: 111 of 361
- Download datasheet (7Mb)
4317J–AVR–08/10
ing a logical one to its I/O bit location. The Waveform Generator uses the match signal to
generate an output according to operating mode set by the Waveform Generation mode
(WGMn3:0) bits and Compare Output mode (COMnx1:0) bits. The TOP and BOTTOM signals
are used by the Waveform Generator for handling the special cases of the extreme values in
some modes of operation
A special feature of Output Compare unit A allows it to define the Timer/Counter TOP value (i.e.,
counter resolution). In addition to the counter resolution, the TOP value defines the period time
for waveforms generated by the Waveform Generator.
Figure 15-4
bit names indicates the device number (n = n for Timer/Counter n), and the “x” indicates Output
Compare unit (x). The elements of the block diagram that are not directly a part of the Output
Compare unit are gray shaded.
Figure 15-4. Output Compare Unit, Block Diagram
The OCRnx Register is double buffered when using any of the twelve Pulse Width Modulation
(PWM) modes. For the Normal and Clear Timer on Compare (CTC) modes of operation, the
double buffering is disabled. The double buffering synchronizes the update of the OCRnx Com-
pare Register to either TOP or BOTTOM of the counting sequence. The synchronization
prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the out-
put glitch-free.
The OCRnx Register access may seem complex, but this is not case. When the double buffering
is enabled, the CPU has access to the OCRnx Buffer Register, and if double buffering is dis-
abled the CPU will access the OCRnx directly. The content of the OCR1x (Buffer or Compare)
Register is only changed by a write operation (the Timer/Counter does not update this register
automatically as the TCNT1 and ICR1 Register). Therefore OCR1x is not read via the high byte
temporary register (TEMP). However, it is a good practice to read the low byte first as when
accessing other 16-bit registers. Writing the OCRnx Registers must be done via the TEMP Reg-
ister since the compare of all 16 bits is done continuously. The high byte (OCRnxH) has to be
written first. When the high byte I/O location is written by the CPU, the TEMP Register will be
shows a block diagram of the Output Compare unit. The small “n” in the register and
OCRnxH Buf. (8-bit)
(See “16-bit Timer/Counter1 with PWM” on page
OCRnxH (8-bit)
BOTTOM
OCRnx Buffer (16-bit Register)
TEMP (8-bit)
TOP
OCRnx (16-bit Register)
OCRnxL Buf. (8-bit)
OCRnxL (8-bit)
DATA BUS
Waveform Generator
WGMn3:0
=
(16-bit Comparator )
(8-bit)
AT90PWM2/3/2B/3B
COMnx1:0
TCNTnH (8-bit)
OCFnx (Int.Req.)
TCNTn (16-bit Counter)
102.)
TCNTnL (8-bit)
OCnx
111
Related parts for AT90PWM2B-16SE
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
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:
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: