ATMEGA168-20PU Atmel, ATMEGA168-20PU Datasheet - Page 117
![IC AVR MCU 16K 20MHZ 28DIP](/photos/7/21/72189/453-28-dip_sml.jpg)
ATMEGA168-20PU
Manufacturer Part Number
ATMEGA168-20PU
Description
IC AVR MCU 16K 20MHZ 28DIP
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheets
1.ATAVRTS2080B.pdf
(378 pages)
2.ATMEGA48-20AU.pdf
(35 pages)
3.ATMEGA88-20MU.pdf
(33 pages)
4.ATMEGA168-20AU.pdf
(359 pages)
Specifications of ATMEGA168-20PU
Core Processor
AVR
Core Size
8-Bit
Speed
20MHz
Connectivity
I²C, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
23
Program Memory Size
16KB (8K x 16)
Program Memory Type
FLASH
Eeprom Size
512 x 8
Ram Size
1K x 8
Voltage - Supply (vcc/vdd)
2.7 V ~ 5.5 V
Data Converters
A/D 6x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
28-DIP (0.300", 7.62mm)
Processor Series
ATMEGA16x
Core
AVR8
Data Bus Width
8 bit
Data Ram Size
1 KB
Interface Type
2-Wire, SPI, USART, Serial
Maximum Clock Frequency
20 MHz
Number Of Programmable I/os
23
Number Of Timers
3
Operating Supply Voltage
2.7 V to 5.5 V
Maximum Operating Temperature
+ 85 C
Mounting Style
Through Hole
3rd Party Development Tools
EWAVR, EWAVR-BL
Development Tools By Supplier
ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
Minimum Operating Temperature
- 40 C
On-chip Adc
10 bit, 6 Channel
A/d Inputs
6-Channel, 10-Bit
Cpu Speed
20 MIPS
Eeprom Memory
512 Bytes
Input Output
23
Interface
I2C/SPI/UART/USART
Memory Type
Flash
Number Of Bits
8
Package Type
28-pin PDIP
Programmable Memory
16K Bytes
Timers
2-8-bit, 1-16-bit
Voltage, Range
4.5-5.5 V
Controller Family/series
AVR MEGA
No. Of I/o's
23
Eeprom Memory Size
512Byte
Ram Memory Size
1KB
Rohs Compliant
Yes
For Use With
ATSTK600-TQFP32 - STK600 SOCKET/ADAPTER 32-TQFPATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
ATMEGA168-20PU
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
- ATAVRTS2080B PDF datasheet
- ATMEGA48-20AU PDF datasheet #2
- ATMEGA88-20MU PDF datasheet #3
- ATMEGA168-20AU PDF datasheet #4
- Current page: 117 of 378
- Download datasheet (8Mb)
15.7.1
15.7.2
15.7.3
2545S–AVR–07/10
Force Output Compare
Compare Match Blocking by TCNT1 Write
Using the Output Compare Unit
prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby making the out-
put glitch-free.
The OCR1x Register access may seem complex, but this is not case. When the double buffering
is enabled, the CPU has access to the OCR1x Buffer Register, and if double buffering is dis-
abled the CPU will access the OCR1x 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 OCR1x Registers must be done via the TEMP Reg-
ister since the compare of all 16 bits is done continuously. The high byte (OCR1xH) has to be
written first. When the high byte I/O location is written by the CPU, the TEMP Register will be
updated by the value written. Then when the low byte (OCR1xL) is written to the lower eight bits,
the high byte will be copied into the upper 8-bits of either the OCR1x buffer or OCR1x Compare
Register in the same system clock cycle.
For more information of how to access the 16-bit registers refer to
on page
In non-PWM Waveform Generation modes, the match output of the comparator can be forced by
writing a one to the Force Output Compare (FOC1x) bit. Forcing compare match will not set the
OCF1x Flag or reload/clear the timer, but the OC1x pin will be updated as if a real compare
match had occurred (the COM11:0 bits settings define whether the OC1x pin is set, cleared or
toggled).
All CPU writes to the TCNT1 Register will block any compare match that occurs in the next timer
clock cycle, even when the timer is stopped. This feature allows OCR1x to be initialized to the
same value as TCNT1 without triggering an interrupt when the Timer/Counter clock is enabled.
Since writing TCNT1 in any mode of operation will block all compare matches for one timer clock
cycle, there are risks involved when changing TCNT1 when using any of the Output Compare
channels, independent of whether the Timer/Counter is running or not. If the value written to
TCNT1 equals the OCR1x value, the compare match will be missed, resulting in incorrect wave-
form generation. Do not write the TCNT1 equal to TOP in PWM modes with variable TOP
values. The compare match for the TOP will be ignored and the counter will continue to 0xFFFF.
Similarly, do not write the TCNT1 value equal to BOTTOM when the counter is downcounting.
The setup of the OC1x should be performed before setting the Data Direction Register for the
port pin to output. The easiest way of setting the OC1x value is to use the Force Output Com-
pare (FOC1x) strobe bits in Normal mode. The OC1x Register keeps its value even when
changing between Waveform Generation modes.
Be aware that the COM1x1:0 bits are not double buffered together with the compare value.
Changing the COM1x1:0 bits will take effect immediately.
109.
ATmega48/88/168
“Accessing 16-bit Registers”
117
Related parts for ATMEGA168-20PU
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![ATmega168](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
![ATmega168 Automotive](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
![ATMEGA168-20AJ](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Manufacturer:
ATMEL Corporation
Datasheet:
![ATMEGA168-20AU](/photos/6/91/69154/313-32-tqfp_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 20MHZ 32TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA168-20MU](/photos/12/13/121319/atmega168-20mu_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 20MHZ 32-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA168-15AZ](/photos/6/91/69154/313-32-tqfp_tmb.jpg)
Part Number:
Description:
MCU AVR 16K FLASH 15MHZ 32-TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA168-15MZ](/photos/30/99/309943/qfn-32_tmb.jpg)
Part Number:
Description:
MCU AVR 16K FLASH 15MHZ 32-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA168-20AI](/photos/6/91/69154/313-32-tqfp_tmb.jpg)
Part Number:
Description:
IC AVR MCU 16K 20MHZ 32TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA168-20MUR](/images/manufacturer_photos/0/0/78/atmel_tmb.jpg)
Part Number:
Description:
MCU AVR 16KB FLASH 20MHZ 32QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA168-20AUR](/photos/6/91/69154/313-32-tqfp_tmb.jpg)
Part Number:
Description:
MCU AVR 16KB FLASH 20MHZ 32TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA168-20MQ](/photos/12/32/123211/atmega168-20mq_tmb.jpg)
Part Number:
Description:
IC MCU AVR 16K FLASH 32-QFN
Manufacturer:
Atmel
Datasheet: