8-bit AVR Microcontrollers
ATmega328/P
DATASHEET COMPLETE
Introduction
The Atmel picoPower ATmega328/P is a low-power CMOS 8-bit
microcontroller based on the AVR
®
enhanced RISC architecture. By
executing powerful instructions in a single clock cycle, the ATmega328/P
achieves throughputs close to 1MIPS per MHz. This empowers system
designer to optimize the device for power consumption versus processing
speed.
®
®
Feature
High Performance, Low Power Atmel
®
AVR
®
8-Bit Microcontroller Family
•
Advanced RISC Architecture
–
131 Powerful Instructions
–
Most Single Clock Cycle Execution
–
32 x 8 General Purpose Working Registers
–
Fully Static Operation
–
Up to 20 MIPS Throughput at 20MHz
–
On-chip 2-cycle Multiplier
•
High Endurance Non-volatile Memory Segments
–
32KBytes of In-System Self-Programmable Flash program
Memory
–
1KBytes EEPROM
–
2KBytes Internal SRAM
–
Write/Erase Cycles: 10,000 Flash/100,000 EEPROM
–
Data Retention: 20 years at 85°C/100 years at 25°C
(1)
–
Optional Boot Code Section with Independent Lock Bits
• In-System Programming by On-chip Boot Program
• True Read-While-Write Operation
–
Programming Lock for Software Security
•
Atmel
®
QTouch
®
Library Support
–
Capacitive Touch Buttons, Sliders and Wheels
–
QTouch and QMatrix
®
Acquisition
–
Up to 64 sense channels
Atmel-42735B-ATmega328/P_Datasheet_Complete-11/2016
•
Peripheral Features
–
Two 8-bit Timer/Counters with Separate Prescaler and Compare Mode
–
One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture Mode
–
Real Time Counter with Separate Oscillator
–
Six PWM Channels
–
8-channel 10-bit ADC in TQFP and QFN/MLF package
• Temperature Measurement
–
6-channel 10-bit ADC in PDIP Package
–
–
–
–
–
–
• Temperature Measurement
Two Master/Slave SPI Serial Interface
One Programmable Serial USART
One Byte-oriented 2-wire Serial Interface (Philips I
2
C compatible)
Programmable Watchdog Timer with Separate On-chip Oscillator
One On-chip Analog Comparator
Interrupt and Wake-up on Pin Change
•
Special Microcontroller Features
–
Power-on Reset and Programmable Brown-out Detection
–
–
–
Internal Calibrated Oscillator
External and Internal Interrupt Sources
•
•
•
•
•
Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby, and
Extended Standby
I/O and Packages
–
23 Programmable I/O Lines
–
28-pin PDIP, 32-lead TQFP, 28-pad QFN/MLF and 32-pad QFN/MLF
Operating Voltage:
–
1.8 - 5.5V
Temperature Range:
–
-40°C to 105°C
Speed Grade:
–
0 - 4MHz @ 1.8 - 5.5V
–
0 - 10MHz @ 2.7 - 5.5V
–
0 - 20MHz @ 4.5 - 5.5V
Power Consumption at 1MHz, 1.8V, 25°C
–
Active Mode: 0.2mA
–
Power-down Mode: 0.1μA
–
Power-save Mode: 0.75μA (Including 32kHz RTC)
Atmel ATmega328/P [DATASHEET]
Atmel-42735B-ATmega328/P_Datasheet_Complete-11/2016
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Table of Contents
Introduction......................................................................................................................1
Feature............................................................................................................................ 1
1. Description.................................................................................................................9
2. Configuration Summary........................................................................................... 10
3. Ordering Information ............................................................................................... 11
3.1.
3.2.
ATmega328 ............................................................................................................................... 11
ATmega328P .............................................................................................................................12
4. Block Diagram......................................................................................................... 13
5. Pin Configurations................................................................................................... 14
5.1.
5.2.
Pin-out........................................................................................................................................ 14
Pin Descriptions..........................................................................................................................17
6. I/O Multiplexing........................................................................................................ 19
7. Resources................................................................................................................21
8. Data Retention.........................................................................................................22
9. About Code Examples............................................................................................. 23
10. Capacitive Touch Sensing....................................................................................... 24
10.1. QTouch Library........................................................................................................................... 24
11. AVR CPU Core........................................................................................................ 25
11.1.
11.2.
11.3.
11.4.
11.5.
11.6.
Overview.....................................................................................................................................25
ALU – Arithmetic Logic Unit........................................................................................................26
Status Register...........................................................................................................................26
General Purpose Register File................................................................................................... 28
Stack Pointer.............................................................................................................................. 29
Instruction Execution Timing...................................................................................................... 31
11.7. Reset and Interrupt Handling..................................................................................................... 32
12. AVR Memories.........................................................................................................34
12.1.
12.2.
12.3.
12.4.
12.5.
12.6.
Overview.....................................................................................................................................34
In-System Reprogrammable Flash Program Memory................................................................ 34
SRAM Data Memory...................................................................................................................35
EEPROM Data Memory............................................................................................................. 36
I/O Memory.................................................................................................................................37
Register Description................................................................................................................... 38
13. System Clock and Clock Options............................................................................ 48
13.1. Clock Systems and Their Distribution.........................................................................................48
13.2. Clock Sources............................................................................................................................ 49
13.3. Low Power Crystal Oscillator......................................................................................................51
13.4. Full Swing Crystal Oscillator.......................................................................................................52
13.5. Low Frequency Crystal Oscillator...............................................................................................53
13.6. Calibrated Internal RC Oscillator................................................................................................54
13.7. 128kHz Internal Oscillator.......................................................................................................... 55
13.8. External Clock............................................................................................................................ 56
13.9. Timer/Counter Oscillator.............................................................................................................57
13.10. Clock Output Buffer....................................................................................................................57
13.11. System Clock Prescaler............................................................................................................. 57
13.12. Register Description...................................................................................................................58
14. PM - Power Management and Sleep Modes...........................................................62
14.1. Overview.....................................................................................................................................62
14.2. Sleep Modes...............................................................................................................................62
14.3. BOD Disable...............................................................................................................................63
14.4. Idle Mode....................................................................................................................................63
14.5. ADC Noise Reduction Mode.......................................................................................................63
14.6. Power-Down Mode.....................................................................................................................64
14.7. Power-save Mode.......................................................................................................................64
14.8. Standby Mode............................................................................................................................ 65
14.9. Extended Standby Mode............................................................................................................ 65
14.10. Power Reduction Register......................................................................................................... 65
14.11. Minimizing Power Consumption................................................................................................. 65
14.12. Register Description...................................................................................................................67
15. SCRST - System Control and Reset....................................................................... 72
15.1.
15.2.
15.3.
15.4.
15.5.
15.6.
15.7.
15.8.
15.9.
Resetting the AVR...................................................................................................................... 72
Reset Sources............................................................................................................................72
Power-on Reset..........................................................................................................................73
External Reset............................................................................................................................74
Brown-out Detection...................................................................................................................74
Watchdog System Reset............................................................................................................ 75
Internal Voltage Reference.........................................................................................................75
Watchdog Timer......................................................................................................................... 76
Register Description................................................................................................................... 78
16. Interrupts................................................................................................................. 82
16.1. Interrupt Vectors in ATmega328/P..............................................................................................82
16.2. Register Description................................................................................................................... 84
17. EXINT - External Interrupts..................................................................................... 87
17.1. Pin Change Interrupt Timing.......................................................................................................87
17.2. Register Description................................................................................................................... 88
18. I/O-Ports.................................................................................................................. 97
18.1. Overview.....................................................................................................................................97
18.2. Ports as General Digital I/O........................................................................................................98
Atmel ATmega328/P [DATASHEET]
Atmel-42735B-ATmega328/P_Datasheet_Complete-11/2016
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18.3. Alternate Port Functions...........................................................................................................101
18.4. Register Description................................................................................................................. 113
19. TC0 - 8-bit Timer/Counter0 with PWM...................................................................125
19.1.
19.2.
19.3.
19.4.
19.5.
19.6.
19.7.
19.8.
19.9.
Features................................................................................................................................... 125
Overview...................................................................................................................................125
Timer/Counter Clock Sources.................................................................................................. 127
Counter Unit............................................................................................................................. 127
Output Compare Unit................................................................................................................128
Compare Match Output Unit.....................................................................................................130
Modes of Operation..................................................................................................................131
Timer/Counter Timing Diagrams...............................................................................................135
Register Description................................................................................................................. 137
20. TC1 - 16-bit Timer/Counter1 with PWM.................................................................149
20.1. Overview...................................................................................................................................149
20.2. Features................................................................................................................................... 149
20.3. Block Diagram.......................................................................................................................... 149
20.4. Definitions.................................................................................................................................150
20.5. Registers.................................................................................................................................. 151
20.6. Accessing 16-bit Registers.......................................................................................................151
20.7. Timer/Counter Clock Sources.................................................................................................. 154
20.8. Counter Unit............................................................................................................................. 154
20.9. Input Capture Unit.................................................................................................................... 155
20.10. Output Compare Units............................................................................................................. 157
20.11. Compare Match Output Unit.....................................................................................................159
20.12. Modes of Operation..................................................................................................................160
20.13. Timer/Counter Timing Diagrams.............................................................................................. 168
20.14. Register Description.................................................................................................................169
21. Timer/Counter 0, 1 Prescalers...............................................................................186
21.1.
21.2.
21.3.
21.4.
Internal Clock Source............................................................................................................... 186
Prescaler Reset........................................................................................................................186
External Clock Source..............................................................................................................186
Register Description................................................................................................................. 187
22. TC2 - 8-bit Timer/Counter2 with PWM and Asynchronous Operation................... 189
22.1. Features................................................................................................................................... 189
22.2. Overview...................................................................................................................................189
22.3. Timer/Counter Clock Sources.................................................................................................. 191
22.4. Counter Unit............................................................................................................................. 191
22.5. Output Compare Unit................................................................................................................192
22.6. Compare Match Output Unit.....................................................................................................194
22.7. Modes of Operation..................................................................................................................195
22.8. Timer/Counter Timing Diagrams...............................................................................................199
22.9. Asynchronous Operation of Timer/Counter2............................................................................ 200
22.10. Timer/Counter Prescaler.......................................................................................................... 202
22.11. Register Description................................................................................................................. 202
Atmel ATmega328/P [DATASHEET]
Atmel-42735B-ATmega328/P_Datasheet_Complete-11/2016
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