ATmega48A/PA/88A/PA/168A/PA/328/P
ATMEL 8-BIT MICROCONTROLLER WITH 4/8/16/32KBYTES
IN-SYSTEM PROGRAMMABLE FLASH
Features
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
̶ 4/8/16/32KBytes of In-System Self-Programmable Flash program memory
̶ 256/512/512/1KBytes EEPROM
̶ 512/1K/1K/2KBytes Internal SRAM
̶ Write/Erase Cycles: 10,000 Flash/100,000 EEPROM
̶ Data retention: 20 years at 85C/100 years at 25C(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
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
̶ Programmable Serial USART
̶ Master/Slave SPI Serial Interface
̶ Byte-oriented 2-wire Serial Interface (Philips I2C compatible)
̶ Programmable Watchdog Timer with Separate On-chip Oscillator
̶ On-chip Analog Comparator
̶ Interrupt and Wake-up on Pin Change
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
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:
̶ -40C to 85C
Speed Grade:
̶ 0 - 4MHz@1.8 - 5.5V, 0 - 10MHz@2.7 - 5.5.V, 0 - 20MHz @ 4.5 - 5.5V
Power Consumption at 1MHz, 1.8V, 25C
̶ Active Mode: 0.2mA
̶ Power-down Mode: 0.1µA
̶ Power-save Mode: 0.75µA (Including 32kHz RTC)
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
2
Pin Configurations
Figure 1-1.
Pinout ATmega48A/PA/88A/PA/168A/PA/328/P
28 PDIP
PD2 (INT0/PCINT18)
PD1 (TXD/PCINT17)
PD0 (RXD/PCINT16)
PC6 (RESET/PCINT14)
PC5 (ADC5/SCL/PCINT13)
PC4 (ADC4/SDA/PCINT12)
PC3 (ADC3/PCINT11)
PC2 (ADC2/PCINT10)
32 TQFP Top View
32
31
30
29
28
27
26
25
(PCINT14/RESET) PC6
(PCINT16/RXD) PD0
(PCINT17/TXD) PD1
(PCINT18/INT0) PD2
(PCINT19/OC2B/INT1) PD3
(PCINT20/XCK/T0) PD4
VCC
GND
(PCINT6/XTAL1/TOSC1) PB6
(PCINT7/XTAL2/TOSC2) PB7
(PCINT21/OC0B/T1) PD5
(PCINT22/OC0A/AIN0) PD6
(PCINT23/AIN1) PD7
(PCINT0/CLKO/ICP1) PB0
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
PC1 (ADC1/PCINT9)
PC0 (ADC0/PCINT8)
ADC7
GND
AREF
ADC6
AVCC
PB5 (SCK/PCINT5)
(PCINT21/OC0B/T1) PD5
(PCINT22/OC0A/AIN0) PD6
(PCINT23/AIN1) PD7
(PCINT0/CLKO/ICP1) PB0
(PCINT1/OC1A) PB1
(PCINT2/SS/OC1B) PB2
(PCINT3/OC2A/MOSI) PB3
(PCINT4/MISO) PB4
9
10
11
12
13
14
15
16
PD2 (INT0/PCINT18)
PD1 (TXD/PCINT17)
PD0 (RXD/PCINT16)
PC6 (RESET/PCINT14)
PC5 (ADC5/SCL/PCINT13)
PC4 (ADC4/SDA/PCINT12)
PC3 (ADC3/PCINT11)
PC2 (ADC2/PCINT10)
(PCINT19/OC2B/INT1) PD3
(PCINT20/XCK/T0) PD4
GND
VCC
GND
VCC
(PCINT6/XTAL1/TOSC1) PB6
(PCINT7/XTAL2/TOSC2) PB7
PC2 (ADC2/PCINT10)
PC1 (ADC1/PCINT9)
PC0 (ADC0/PCINT8)
GND
AREF
AVCC
PB5 (SCK/PCINT5)
Table 1-1.
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
PC1 (ADC1/PCINT9)
PC0 (ADC0/PCINT8)
ADC7
GND
AREF
ADC6
AVCC
PB5 (SCK/PCINT5)
9
10
11
12
13
14
15
16
8
9
10
11
12
13
14
NOTE: Bottom pad should be soldered to ground.
PC5 (ADC5/SCL/PCINT13)
PC4 (ADC4/SDA/PCINT12)
PC3 (ADC3/PCINT11)
PC2 (ADC2/PCINT10)
PC1 (ADC1/PCINT9)
PC0 (ADC0/PCINT8)
GND
AREF
AVCC
PB5 (SCK/PCINT5)
PB4 (MISO/PCINT4)
PB3 (MOSI/OC2A/PCINT3)
PB2 (SS/OC1B/PCINT2)
PB1 (OC1A/PCINT1)
32
31
30
29
28
27
26
25
PD2 (INT0/PCINT18)
PD1 (TXD/PCINT17)
PD0 (RXD/PCINT16)
PC6 (RESET/PCINT14)
PC5 (ADC5/SCL/PCINT13)
PC4 (ADC4/SDA/PCINT12)
PC3 (ADC3/PCINT11)
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
28
27
26
25
24
23
22
21
20
19
18
17
16
15
32 MLF Top View
28 MLF Top View
(PCINT19/OC2B/INT1) PD3
(PCINT20/XCK/T0) PD4
VCC
GND
(PCINT6/XTAL1/TOSC1) PB6
(PCINT7/XTAL2/TOSC2) PB7
(PCINT21/OC0B/T1) PD5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
NOTE: Bottom pad should be soldered to ground.
(PCINT21/OC0B/T1) PD5
(PCINT22/OC0A/AIN0) PD6
(PCINT23/AIN1) PD7
(PCINT0/CLKO/ICP1) PB0
(PCINT1/OC1A) PB1
(PCINT2/SS/OC1B) PB2
(PCINT3/OC2A/MOSI) PB3
(PCINT4/MISO) PB4
(PCINT19/OC2B/INT1) PD3
(PCINT20/XCK/T0) PD4
GND
VCC
GND
VCC
(PCINT6/XTAL1/TOSC1) PB6
(PCINT7/XTAL2/TOSC2) PB7
(PCINT22/OC0A/AIN0) PD6
(PCINT23/AIN1) PD7
(PCINT0/CLKO/ICP1) PB0
(PCINT1/OC1A) PB1
(PCINT2/SS/OC1B) PB2
(PCINT3/OC2A/MOSI) PB3
(PCINT4/MISO) PB4
1.
32UFBGA - Pinout ATmega48A/48PA/88A/88PA/168A/168PA
1
2
3
4
5
6
A
PD2
PD1
PC6
PC4
PC2
PC1
B
PD3
PD4
PD0
PC5
PC3
PC0
C
GND
GND
ADC7
GND
D
VDD
VDD
AREF
ADC6
E
PB6
PD6
PB0
PB2
AVDD
PB5
F
PB7
PD5
PD7
PB1
PB3
PB4
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
3
1.1
Pin Descriptions
1.1.1
VCC
Digital supply voltage.
1.1.2
GND
Ground.
1.1.3
Port B (PB7:0) XTAL1/XTAL2/TOSC1/TOSC2
Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output
buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins
that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tristated when a reset condition becomes active, even if the clock is not running.
Depending on the clock selection fuse settings, PB6 can be used as input to the inverting Oscillator amplifier
and input to the internal clock operating circuit.
Depending on the clock selection fuse settings, PB7 can be used as output from the inverting Oscillator
amplifier.
If the Internal Calibrated RC Oscillator is used as chip clock source, PB7...6 is used as TOSC2...1 input for the
Asynchronous Timer/Counter2 if the AS2 bit in ASSR is set.
The various special features of Port B are elaborated in ”Alternate Functions of Port B” on page 82 and ”System
Clock and Clock Options” on page 27.
1.1.4
Port C (PC5:0)
Port C is a 7-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The PC5...0 output
buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port C pins
that are externally pulled low will source current if the pull-up resistors are activated. The Port C pins are tristated when a reset condition becomes active, even if the clock is not running.
1.1.5
PC6/RESET
If the RSTDISBL Fuse is programmed, PC6 is used as an I/O pin. Note that the electrical characteristics of PC6
differ from those of the other pins of Port C.
If the RSTDISBL Fuse is unprogrammed, PC6 is used as a Reset input. A low level on this pin for longer than
the minimum pulse length will generate a Reset, even if the clock is not running. The minimum pulse length is
given in Table 29-11 on page 305. Shorter pulses are not guaranteed to generate a Reset.
The various special features of Port C are elaborated in ”Alternate Functions of Port C” on page 85.|
1.1.6
Port D (PD7:0)
Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port D output
buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port D pins
that are externally pulled low will source current if the pull-up resistors are activated. The Port D pins are tristated when a reset condition becomes active, even if the clock is not running.
The various special features of Port D are elaborated in ”Alternate Functions of Port D” on page 88.
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
4
1.1.7
AVCC
AVCC is the supply voltage pin for the A/D Converter, PC3:0, and ADC7:6. It should be externally connected to
VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter.
Note that PC6...4 use digital supply voltage, VCC.
1.1.8
AREF
AREF is the analog reference pin for the A/D Converter.
1.1.9
ADC7:6 (TQFP and QFN/MLF Package Only)
In the TQFP and QFN/MLF package, ADC7:6 serve as analog inputs to the A/D converter. These pins are
powered from the analog supply and serve as 10-bit ADC channels.
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
5
2.
Overview
The ATmega48A/PA/88A/PA/168A/PA/328/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
ATmega48A/PA/88A/PA/168A/PA/328/P achieves throughputs approaching 1 MIPS per MHz allowing the
system designer to optimize power consumption versus processing speed.
Block Diagram
VCC
Block Diagram
GND
Figure 2-1.
Watchdog
Timer
Watchdog
Oscillator
Oscillator
Circuits /
Clock
Generation
Power
Supervision
POR / BOD &
RESET
debugWIRE
Flash
SRAM
PROGRAM
LOGIC
CPU
EEPROM
AVCC
AREF
GND
DATABUS
2.1
2
8bit T/C 0
16bit T/C 1
A/D Conv.
8bit T/C 2
Analog
Comp.
Internal
Bandgap
USART 0
SPI
TWI
PORT D (8)
PORT B (8)
PORT C (7)
6
RESET
XTAL[1..2]
PD[0..7]
PB[0..7]
PC[0..6]
ADC[6..7]
The AVR core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are
directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one
single instruction executed in one clock cycle. The resulting architecture is more code efficient while achieving
throughputs up to ten times faster than conventional CISC microcontrollers.
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
6
The ATmega48A/PA/88A/PA/168A/PA/328/P provides the following features: 4K/8Kbytes of In-System
Programmable Flash with Read-While-Write capabilities, 256/512/512/1Kbytes EEPROM, 512/1K/1K/2Kbytes
SRAM, 23 general purpose I/O lines, 32 general purpose working registers, three flexible Timer/Counters with
compare modes, internal and external interrupts, a serial programmable USART, a byte-oriented 2-wire Serial
Interface, an SPI serial port, a 6-channel 10-bit ADC (8 channels in TQFP and QFN/MLF packages), a
programmable Watchdog Timer with internal Oscillator, and five software selectable power saving modes. The
Idle mode stops the CPU while allowing the SRAM, Timer/Counters, USART, 2-wire Serial Interface, SPI port,
and interrupt system to continue functioning. The Power-down mode saves the register contents but freezes the
Oscillator, disabling all other chip functions until the next interrupt or hardware reset. In Power-save mode, the
asynchronous timer continues to run, allowing the user to maintain a timer base while the rest of the device is
sleeping. The ADC Noise Reduction mode stops the CPU and all I/O modules except asynchronous timer and
ADC, to minimize switching noise during ADC conversions. In Standby mode, the crystal/resonator Oscillator is
running while the rest of the device is sleeping. This allows very fast start-up combined with low power
consumption.
Atmel® offers the QTouch® library for embedding capacitive touch buttons, sliders and wheels functionality into
AVR® microcontrollers. The patented charge-transfer signal acquisition offers robust sensing and includes fully
debounced reporting of touch keys and includes Adjacent Key Suppression® (AKS™) technology for
unambiguous detection of key events. The easy-to-use QTouch Suite toolchain allows you to explore, develop
and debug your own touch applications.
The device is manufactured using Atmel’s high density non-volatile memory technology. The On-chip ISP Flash
allows the program memory to be reprogrammed In-System through an SPI serial interface, by a conventional
non-volatile memory programmer, or by an On-chip Boot program running on the AVR core. The Boot program
can use any interface to download the application program in the Application Flash memory. Software in the
Boot Flash section will continue to run while the Application Flash section is updated, providing true ReadWhile-Write operation. By combining an 8-bit RISC CPU with In-System Self-Programmable Flash on a
monolithic chip, the Atmel ATmega48A/PA/88A/PA/168A/PA/328/P is a powerful microcontroller that provides a
highly flexible and cost effective solution to many embedded control applications.
The ATmega48A/PA/88A/PA/168A/PA/328/P AVR is supported with a full suite of program and system
development tools including: C Compilers, Macro Assemblers, Program Debugger/Simulators, In-Circuit
Emulators, and Evaluation kits.
2.2
Comparison Between Processors
The ATmega48A/PA/88A/PA/168A/PA/328/P differ only in memory sizes, boot loader support, and interrupt
vector sizes. Table 2-1 summarizes the different memory and interrupt vector sizes for the devices.
Table 2-1.
Memory Size Summary
Device
Flash
EEPROM
RAM
Interrupt Vector Size
ATmega48A
4KBytes
256Bytes
512Bytes
1 instruction word/vector
ATmega48PA
4KBytes
256Bytes
512Bytes
1 instruction word/vector
ATmega88A
8KBytes
512Bytes
1KBytes
1 instruction word/vector
ATmega88PA
8KBytes
512Bytes
1KBytes
1 instruction word/vector
ATmega168A
16KBytes
512Bytes
1KBytes
2 instruction words/vector
ATmega168PA
16KBytes
512Bytes
1KBytes
2 instruction words/vector
ATmega328
32KBytes
1KBytes
2KBytes
2 instruction words/vector
ATmega328P
32KBytes
1KBytes
2KBytes
2 instruction words/vector
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
7
ATmega48A/PA/88A/PA/168A/PA/328/P support a real Read-While-Write Self-Programming mechanism.
There is a separate Boot Loader Section, and the SPM instruction can only execute from there. In ATmega
48A/48PA there is no Read-While-Write support and no separate Boot Loader Section. The SPM instruction can
execute from the entire Flash
3.
Resources
A comprehensive set of development tools, application notes and datasheets are available for download on
http://www.atmel.com/avr.
Note:
4.
1.
Data Retention
Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over
20 years at 85°C or 100 years at 25°C.
5.
About Code Examples
This documentation contains simple code examples that briefly show how to use various parts of the device.
These code examples assume that the part specific header file is included before compilation. Be aware that not
all C compiler vendors include bit definitions in the header files and interrupt handling in C is compiler
dependent. Please confirm with the C compiler documentation for more details.
For I/O Registers located in extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI” instructions must
be replaced with instructions that allow access to extended I/O. Typically “LDS” and “STS” combined with
“SBRS”, “SBRC”, “SBR”, and “CBR”.
6.
Capacitive Touch Sensing
The Atmel® QTouch® Library provides a simple to use solution to realize touch sensitive interfaces on most
Atmel AVR® microcontrollers. The QTouch Library includes support for the Atmel QTouch and Atmel QMatrix®
acquisition methods.
Touch sensing can be added to any application by linking the appropriate Atmel QTouch Library for the AVR
Microcontroller. This is done by using a simple set of APIs to define the touch channels and sensors, and then
calling the touch sensing APIs to retrieve the channel information and determine the touch sensor states.
The QTouch Library is FREE and downloadable from the Atmel website at the following location:
www.atmel.com/qtouchlibrary. For implementation details and other information, refer to the Atmel QTouch
Library User Guide - also available for download from Atmel website.
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
8
7.
Register Summary
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Page
(0xFF)
Reserved
–
–
–
–
–
–
–
–
(0xFE)
Reserved
–
–
–
–
–
–
–
–
(0xFD)
Reserved
–
–
–
–
–
–
–
–
(0xFC)
Reserved
–
–
–
–
–
–
–
–
(0xFB)
Reserved
–
–
–
–
–
–
–
–
(0xFA)
Reserved
–
–
–
–
–
–
–
–
(0xF9)
Reserved
–
–
–
–
–
–
–
–
(0xF8)
Reserved
–
–
–
–
–
–
–
–
(0xF7)
Reserved
–
–
–
–
–
–
–
–
(0xF6)
Reserved
–
–
–
–
–
–
–
–
(0xF5)
Reserved
–
–
–
–
–
–
–
–
(0xF4)
Reserved
–
–
–
–
–
–
–
–
(0xF3)
Reserved
–
–
–
–
–
–
–
–
(0xF2)
Reserved
–
–
–
–
–
–
–
–
(0xF1)
Reserved
–
–
–
–
–
–
–
–
(0xF0)
Reserved
–
–
–
–
–
–
–
–
(0xEF)
Reserved
–
–
–
–
–
–
–
–
(0xEE)
Reserved
–
–
–
–
–
–
–
–
(0xED)
Reserved
–
–
–
–
–
–
–
–
(0xEC)
Reserved
–
–
–
–
–
–
–
–
(0xEB)
Reserved
–
–
–
–
–
–
–
–
(0xEA)
Reserved
–
–
–
–
–
–
–
–
(0xE9)
Reserved
–
–
–
–
–
–
–
–
(0xE8)
Reserved
–
–
–
–
–
–
–
–
(0xE7)
Reserved
–
–
–
–
–
–
–
–
(0xE6)
Reserved
–
–
–
–
–
–
–
–
(0xE5)
Reserved
–
–
–
–
–
–
–
–
(0xE4)
Reserved
–
–
–
–
–
–
–
–
(0xE3)
Reserved
–
–
–
–
–
–
–
–
(0xE2)
Reserved
–
–
–
–
–
–
–
–
(0xE1)
Reserved
–
–
–
–
–
–
–
–
(0xE0)
Reserved
–
–
–
–
–
–
–
–
(0xDF)
Reserved
–
–
–
–
–
–
–
–
(0xDE)
Reserved
–
–
–
–
–
–
–
–
(0xDD)
Reserved
–
–
–
–
–
–
–
–
(0xDC)
Reserved
–
–
–
–
–
–
–
–
(0xDB)
Reserved
–
–
–
–
–
–
–
–
(0xDA)
Reserved
–
–
–
–
–
–
–
–
(0xD9)
Reserved
–
–
–
–
–
–
–
–
(0xD8)
Reserved
–
–
–
–
–
–
–
–
(0xD7)
Reserved
–
–
–
–
–
–
–
–
(0xD6)
Reserved
–
–
–
–
–
–
–
–
(0xD5)
Reserved
–
–
–
–
–
–
–
–
(0xD4)
Reserved
–
–
–
–
–
–
–
–
(0xD3)
Reserved
–
–
–
–
–
–
–
–
(0xD2)
Reserved
–
–
–
–
–
–
–
–
(0xD1)
Reserved
–
–
–
–
–
–
–
–
(0xD0)
Reserved
–
–
–
–
–
–
–
–
(0xCF)
Reserved
–
–
–
–
–
–
–
–
(0xCE)
Reserved
–
–
–
–
–
–
–
–
(0xCD)
Reserved
–
–
–
–
–
–
–
–
(0xCC)
Reserved
–
–
–
–
–
–
–
–
(0xCB)
Reserved
–
–
–
–
–
–
–
–
(0xCA)
Reserved
–
–
–
–
–
–
–
–
(0xC9)
Reserved
–
–
–
–
–
–
–
–
(0xC8)
Reserved
–
–
–
–
–
–
–
–
(0xC7)
Reserved
–
–
–
–
–
–
–
–
(0xC6)
UDR0
(0xC5)
UBRR0H
(0xC4)
UBRR0L
(0xC3)
Reserved
–
–
–
–
–
–
–
–
(0xC2)
UCSR0C
UMSEL01
UMSEL00
UPM01
UPM00
USBS0
UCSZ01 /UDORD0
UCSZ00 / UCPHA0
UCPOL0
193/204
(0xC1)
UCSR0B
RXCIE0
TXCIE0
UDRIE0
RXEN0
TXEN0
UCSZ02
RXB80
TXB80
192
USART I/O Data Register
191
USART Baud Rate Register High
195
USART Baud Rate Register Low
195
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
9
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Page
(0xC0)
UCSR0A
RXC0
TXC0
UDRE0
FE0
DOR0
UPE0
U2X0
MPCM0
191
(0xBF)
Reserved
–
–
–
–
–
–
–
–
–
(0xBE)
Reserved
–
–
–
–
–
–
–
(0xBD)
TWAMR
TWAM6
TWAM5
TWAM4
TWAM3
TWAM2
TWAM1
TWAM0
–
(0xBC)
TWCR
TWINT
TWEA
TWSTA
TWSTO
TWWC
TWEN
–
TWIE
(0xBB)
TWDR
2-wire Serial Interface Data Register
233
230
232
(0xBA)
TWAR
TWA6
TWA5
TWA4
TWA3
TWA2
TWA1
TWA0
TWGCE
232
(0xB9)
TWSR
TWS7
TWS6
TWS5
TWS4
TWS3
–
TWPS1
TWPS0
231
(0xB8)
TWBR
(0xB7)
Reserved
–
2-wire Serial Interface Bit Rate Register
230
–
–
–
–
–
–
(0xB6)
ASSR
–
EXCLK
AS2
TCN2UB
OCR2AUB
OCR2BUB
TCR2AUB
TCR2BUB
(0xB5)
Reserved
–
–
–
–
–
–
–
–
(0xB4)
OCR2B
Timer/Counter2 Output Compare Register B
157
(0xB3)
OCR2A
Timer/Counter2 Output Compare Register A
157
Timer/Counter2 (8-bit)
158
(0xB2)
TCNT2
(0xB1)
TCCR2B
FOC2A
FOC2B
–
–
WGM22
CS22
CS21
CS20
157
156
153
(0xB0)
TCCR2A
COM2A1
COM2A0
COM2B1
COM2B0
–
–
WGM21
WGM20
(0xAF)
Reserved
–
–
–
–
–
–
–
–
(0xAE)
Reserved
–
–
–
–
–
–
–
–
(0xAD)
Reserved
–
–
–
–
–
–
–
–
(0xAC)
Reserved
–
–
–
–
–
–
–
–
(0xAB)
Reserved
–
–
–
–
–
–
–
–
(0xAA)
Reserved
–
–
–
–
–
–
–
–
(0xA9)
Reserved
–
–
–
–
–
–
–
–
(0xA8)
Reserved
–
–
–
–
–
–
–
–
(0xA7)
Reserved
–
–
–
–
–
–
–
–
(0xA6)
Reserved
–
–
–
–
–
–
–
–
(0xA5)
Reserved
–
–
–
–
–
–
–
–
(0xA4)
Reserved
–
–
–
–
–
–
–
–
(0xA3)
Reserved
–
–
–
–
–
–
–
–
(0xA2)
Reserved
–
–
–
–
–
–
–
–
(0xA1)
Reserved
–
–
–
–
–
–
–
–
(0xA0)
Reserved
–
–
–
–
–
–
–
–
(0x9F)
Reserved
–
–
–
–
–
–
–
–
(0x9E)
Reserved
–
–
–
–
–
–
–
–
(0x9D)
Reserved
–
–
–
–
–
–
–
–
(0x9C)
Reserved
–
–
–
–
–
–
–
–
(0x9B)
Reserved
–
–
–
–
–
–
–
–
(0x9A)
Reserved
–
–
–
–
–
–
–
–
(0x99)
Reserved
–
–
–
–
–
–
–
–
(0x98)
Reserved
–
–
–
–
–
–
–
–
(0x97)
Reserved
–
–
–
–
–
–
–
–
(0x96)
Reserved
–
–
–
–
–
–
–
–
(0x95)
Reserved
–
–
–
–
–
–
–
–
(0x94)
Reserved
–
–
–
–
–
–
–
–
(0x93)
Reserved
–
–
–
–
–
–
–
–
(0x92)
Reserved
–
–
–
–
–
–
–
–
(0x91)
Reserved
–
–
–
–
–
–
–
–
(0x90)
Reserved
–
–
–
–
–
–
–
–
(0x8F)
Reserved
–
–
–
–
–
–
–
–
(0x8E)
Reserved
–
–
–
–
–
–
–
–
(0x8D)
Reserved
–
–
–
–
–
–
–
–
(0x8C)
Reserved
–
–
–
–
–
–
–
–
(0x8B)
OCR1BH
Timer/Counter1 - Output Compare Register B High Byte
(0x8A)
OCR1BL
Timer/Counter1 - Output Compare Register B Low Byte
135
(0x89)
OCR1AH
Timer/Counter1 - Output Compare Register A High Byte
135
(0x88)
OCR1AL
Timer/Counter1 - Output Compare Register A Low Byte
135
(0x87)
ICR1H
Timer/Counter1 - Input Capture Register High Byte
135
(0x86)
ICR1L
Timer/Counter1 - Input Capture Register Low Byte
135
(0x85)
TCNT1H
Timer/Counter1 - Counter Register High Byte
134
(0x84)
TCNT1L
Timer/Counter1 - Counter Register Low Byte
(0x83)
Reserved
–
–
–
(0x82)
TCCR1C
FOC1A
FOC1B
–
–
–
–
–
–
134
(0x81)
TCCR1B
ICNC1
ICES1
–
WGM13
WGM12
CS12
CS11
CS10
133
131
–
–
135
134
–
–
–
(0x80)
TCCR1A
COM1A1
COM1A0
COM1B1
COM1B0
–
–
WGM11
WGM10
(0x7F)
DIDR1
–
–
–
–
–
–
AIN1D
AIN0D
236
(0x7E)
DIDR0
–
–
ADC5D
ADC4D
ADC3D
ADC2D
ADC1D
ADC0D
251
(0x7D)
Reserved
–
–
–
–
–
–
–
–
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
10
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
(0x7C)
ADMUX
REFS1
REFS0
ADLAR
–
MUX3
MUX2
MUX1
MUX0
248
(0x7B)
ADCSRB
–
ACME
–
–
–
ADTS2
ADTS1
ADTS0
251
(0x7A)
ADCSRA
ADEN
ADSC
ADATE
ADIF
ADIE
ADPS2
ADPS1
ADPS0
(0x79)
ADCH
ADC Data Register High byte
Page
249
250
(0x78)
ADCL
(0x77)
Reserved
–
–
–
ADC Data Register Low byte
–
–
–
–
–
250
(0x76)
Reserved
–
–
–
–
–
–
–
–
(0x75)
Reserved
–
–
–
–
–
–
–
–
(0x74)
Reserved
–
–
–
–
–
–
–
–
(0x73)
Reserved
–
–
–
–
–
–
–
–
(0x72)
Reserved
–
–
–
–
–
–
–
–
(0x71)
Reserved
–
–
–
–
–
–
–
–
(0x70)
TIMSK2
–
–
–
–
–
OCIE2B
OCIE2A
TOIE2
157
(0x6F)
TIMSK1
–
–
ICIE1
–
–
OCIE1B
OCIE1A
TOIE1
135
(0x6E)
TIMSK0
–
–
–
–
–
OCIE0B
OCIE0A
TOIE0
109
(0x6D)
PCMSK2
PCINT23
PCINT22
PCINT21
PCINT20
PCINT19
PCINT18
PCINT17
PCINT16
74
(0x6C)
PCMSK1
–
PCINT14
PCINT13
PCINT12
PCINT11
PCINT10
PCINT9
PCINT8
74
(0x6B)
PCMSK0
PCINT7
PCINT6
PCINT5
PCINT4
PCINT3
PCINT2
PCINT1
PCINT0
74
(0x6A)
Reserved
–
–
–
–
–
–
–
–
(0x69)
EICRA
–
–
–
–
ISC11
ISC10
ISC01
ISC00
(0x68)
PCICR
–
–
–
–
–
PCIE2
PCIE1
PCIE0
(0x67)
Reserved
–
–
–
–
–
–
–
–
(0x66)
OSCCAL
(0x65)
Reserved
–
–
–
–
–
–
–
–
Oscillator Calibration Register
71
37
(0x64)
PRR
PRTWI
PRTIM2
PRTIM0
–
PRTIM1
PRSPI
PRUSART0
PRADC
(0x63)
Reserved
–
–
–
–
–
–
–
–
(0x62)
Reserved
–
–
–
–
–
–
–
–
(0x61)
CLKPR
CLKPCE
–
–
–
CLKPS3
CLKPS2
CLKPS1
CLKPS0
(0x60)
WDTCSR
WDIF
WDIE
WDP3
WDCE
WDE
WDP2
WDP1
WDP0
54
0x3F (0x5F)
SREG
I
T
H
S
V
N
Z
C
10
0x3E (0x5E)
SPH
–
–
–
–
–
(SP10) 5.
SP9
SP8
13
0x3D (0x5D)
SPL
SP7
SP6
SP5
SP4
SP3
SP2
SP1
SP0
13
0x3C (0x5C)
Reserved
–
–
–
–
–
–
–
–
0x3B (0x5B)
Reserved
–
–
–
–
–
–
–
–
0x3A (0x5A)
Reserved
–
–
–
–
–
–
–
–
0x39 (0x59)
Reserved
–
–
–
–
–
–
–
–
0x38 (0x58)
Reserved
–
–
–
–
–
–
–
–
0x37 (0x57)
SPMCSR
SPMIE
(RWWSB)5.
SIGRD
(RWWSRE)5.
BLBSET
PGWRT
PGERS
SPMEN
0x36 (0x56)
Reserved
–
–
–
–
–
–
–
–
0x35 (0x55)
MCUCR
–
BODS(6)
BODSE(6)
PUD
–
–
IVSEL
IVCE
0x34 (0x54)
MCUSR
–
–
–
–
WDRF
BORF
EXTRF
PORF
54
0x33 (0x53)
SMCR
–
–
–
–
SM2
SM1
SM0
SE
40
0x32 (0x52)
Reserved
–
–
–
–
–
–
–
–
0x31 (0x51)
Reserved
–
–
–
–
–
–
–
–
0x30 (0x50)
ACSR
ACD
ACBG
ACO
ACI
ACIE
ACIC
ACIS1
ACIS0
0x2F (0x4F)
Reserved
–
–
–
–
–
–
–
–
0x2E (0x4E)
SPDR
0x2D (0x4D)
SPSR
SPIF
WCOL
–
–
–
–
–
SPI2X
168
0x2C (0x4C)
SPCR
SPIE
SPE
DORD
MSTR
CPOL
CPHA
SPR1
SPR0
167
0x2B (0x4B)
GPIOR2
General Purpose I/O Register 2
0x2A (0x4A)
GPIOR1
General Purpose I/O Register 1
0x29 (0x49)
Reserved
0x28 (0x48)
OCR0B
Timer/Counter0 Output Compare Register B
0x27 (0x47)
OCR0A
Timer/Counter0 Output Compare Register A
0x26 (0x46)
TCNT0
0x25 (0x45)
TCCR0B
FOC0A
FOC0B
–
–
WGM02
CS02
CS01
CS00
0x24 (0x44)
TCCR0A
COM0A1
COM0A0
COM0B1
COM0B0
–
–
WGM01
WGM00
0x23 (0x43)
GTCCR
TSM
–
–
–
–
–
PSRASY
PSRSYNC
0x22 (0x42)
EEARH
(EEPROM Address Register High Byte) 5.
0x21 (0x41)
EEARL
EEPROM Address Register Low Byte
22
0x20 (0x40)
EEDR
EEPROM Data Register
22
SPI Data Register
–
–
–
–
42
37
278
45/68/91
235
169
26
26
–
–
–
–
Timer/Counter0 (8-bit)
–
–
EEPM1
EEPM0
EERIE
140/159
22
0x1F (0x3F)
EECR
0x1E (0x3E)
GPIOR0
EEMPE
EEPE
EERE
22
0x1D (0x3D)
EIMSK
–
–
–
–
–
–
INT1
INT0
72
0x1C (0x3C)
EIFR
–
–
–
–
–
–
0x1B (0x3B)
PCIFR
–
–
–
–
–
PCIF2
INTF1
INTF0
72
PCIF1
PCIF0
0x1A (0x3A)
Reserved
–
–
–
–
–
–
–
–
0x19 (0x39)
Reserved
–
–
–
–
–
–
–
–
General Purpose I/O Register 0
26
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
11
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0x18 (0x38)
Reserved
–
–
–
–
–
–
–
–
Page
0x17 (0x37)
TIFR2
–
–
–
–
–
OCF2B
OCF2A
TOV2
158
0x16 (0x36)
TIFR1
–
–
ICF1
–
–
OCF1B
OCF1A
TOV1
136
0x15 (0x35)
TIFR0
–
–
–
–
–
OCF0B
OCF0A
TOV0
0x14 (0x34)
Reserved
–
–
–
–
–
–
–
–
0x13 (0x33)
Reserved
–
–
–
–
–
–
–
–
0x12 (0x32)
Reserved
–
–
–
–
–
–
–
–
0x11 (0x31)
Reserved
–
–
–
–
–
–
–
–
0x10 (0x30)
Reserved
–
–
–
–
–
–
–
–
0x0F (0x2F)
Reserved
–
–
–
–
–
–
–
–
0x0E (0x2E)
Reserved
–
–
–
–
–
–
–
–
0x0D (0x2D)
Reserved
–
–
–
–
–
–
–
–
0x0C (0x2C)
Reserved
–
–
–
–
–
–
–
–
0x0B (0x2B)
PORTD
PORTD7
PORTD6
PORTD5
PORTD4
PORTD3
PORTD2
PORTD1
PORTD0
92
0x0A (0x2A)
DDRD
DDD7
DDD6
DDD5
DDD4
DDD3
DDD2
DDD1
DDD0
92
0x09 (0x29)
PIND
PIND7
PIND6
PIND5
PIND4
PIND3
PIND2
PIND1
PIND0
92
0x08 (0x28)
PORTC
–
PORTC6
PORTC5
PORTC4
PORTC3
PORTC2
PORTC1
PORTC0
91
0x07 (0x27)
DDRC
–
DDC6
DDC5
DDC4
DDC3
DDC2
DDC1
DDC0
91
92
0x06 (0x26)
PINC
–
PINC6
PINC5
PINC4
PINC3
PINC2
PINC1
PINC0
0x05 (0x25)
PORTB
PORTB7
PORTB6
PORTB5
PORTB4
PORTB3
PORTB2
PORTB1
PORTB0
91
0x04 (0x24)
DDRB
DDB7
DDB6
DDB5
DDB4
DDB3
DDB2
DDB1
DDB0
91
0x03 (0x23)
PINB
PINB7
PINB6
PINB5
PINB4
PINB3
PINB2
PINB1
PINB0
91
0x02 (0x22)
Reserved
–
–
–
–
–
–
–
–
0x01 (0x21)
Reserved
–
–
–
–
–
–
–
–
0x0 (0x20)
Reserved
–
–
–
–
–
–
–
–
Note:
1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory
addresses should never be written.
2.
3.
4.
5.
6.
I/O Registers within the address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. In these registers, the value of single bits
can be checked by using the SBIS and SBIC instructions.
Some of the Status Flags are cleared by writing a logical one to them. Note that, unlike most other AVRs, the CBI and SBI instructions will only operate on
the specified bit, and can therefore be used on registers containing such Status Flags. The CBI and SBI instructions work with registers 0x00 to 0x1F only.
When using the I/O specific commands IN and OUT, the I/O addresses 0x00 - 0x3F must be used. When addressing I/O Registers as data space using LD
and ST instructions, 0x20 must be added to these addresses. The ATmega48A/PA/88A/PA/168A/PA/328/P is a complex microcontroller with more
peripheral units than can be supported within the 64 location reserved in Opcode for the IN and OUT instructions. For the Extended I/O space from 0x60 0xFF in SRAM, only the ST/STS/STD and LD/LDS/LDD instructions can be used.
Only valid for ATmega88A/88PA/168A/168PA/328/328P.
BODS and BODSE only available for picoPower devices ATmega48PA/88PA/168PA/328P
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271JS-AVR- ATmega-Datasheet_11/2015
12
8.
Instruction Set Summary
Mnemonics
Operands
Description
Operation
Flags
#Clocks
ARITHMETIC AND LOGIC INSTRUCTIONS
ADD
Rd, Rr
Add two Registers
Rd Rd + Rr
Z,C,N,V,H
1
ADC
Rd, Rr
Add with Carry two Registers
Rd Rd + Rr + C
Z,C,N,V,H
1
2
ADIW
Rdl,K
Add Immediate to Word
Rdh:Rdl Rdh:Rdl + K
Z,C,N,V,S
SUB
Rd, Rr
Subtract two Registers
Rd Rd - Rr
Z,C,N,V,H
1
SUBI
Rd, K
Subtract Constant from Register
Rd Rd - K
Z,C,N,V,H
1
SBC
Rd, Rr
Subtract with Carry two Registers
Rd Rd - Rr - C
Z,C,N,V,H
1
SBCI
Rd, K
Subtract with Carry Constant from Reg.
Rd Rd - K - C
Z,C,N,V,H
1
SBIW
Rdl,K
Subtract Immediate from Word
Rdh:Rdl Rdh:Rdl - K
Z,C,N,V,S
2
AND
Rd, Rr
Logical AND Registers
Rd Rd Rr
Z,N,V
1
ANDI
Rd, K
Logical AND Register and Constant
Rd Rd K
Z,N,V
1
OR
Rd, Rr
Logical OR Registers
Rd Rd v Rr
Z,N,V
1
ORI
Rd, K
Logical OR Register and Constant
Rd Rd v K
Z,N,V
1
EOR
Rd, Rr
Exclusive OR Registers
Rd Rd Rr
Z,N,V
1
COM
Rd
One’s Complement
Rd 0xFF Rd
Z,C,N,V
1
NEG
Rd
Two’s Complement
Rd 0x00 Rd
Z,C,N,V,H
1
SBR
Rd,K
Set Bit(s) in Register
Rd Rd v K
Z,N,V
1
CBR
Rd,K
Clear Bit(s) in Register
Rd Rd (0xFF - K)
Z,N,V
1
INC
Rd
Increment
Rd Rd + 1
Z,N,V
1
DEC
Rd
Decrement
Rd Rd 1
Z,N,V
1
TST
Rd
Test for Zero or Minus
Rd Rd Rd
Z,N,V
1
CLR
Rd
Clear Register
Rd Rd Rd
Z,N,V
1
SER
Rd
Set Register
Rd 0xFF
None
1
MUL
Rd, Rr
Multiply Unsigned
R1:R0 Rd x Rr
Z,C
2
MULS
Rd, Rr
Multiply Signed
R1:R0 Rd x Rr
Z,C
2
MULSU
Rd, Rr
Multiply Signed with Unsigned
R1:R0 Rd x Rr
Z,C
2
FMUL
Rd, Rr
Fractional Multiply Unsigned
R1:R0 (Rd x Rr)