Features
•
High performance, low power Atmel
®
AVR
®
8-bit microcontroller
•
Advanced RISC architecture
– 131 powerful instructions – most single clock cycle execution
– 32 × 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 Kbytes of in-system self-programmable flash program memory
– 256/512/512 bytes EEPROM
– 512/1K/1Kbytes internal SRAM
– Write/erase cyles: 10,000 flash/100,000 EEPROM
– Data retention: 20 years at 85°C/100 years at 25°C
()
– 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
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
– 6-channel 10-bit ADC in PDIP Package
– Programmable serial USART
– Master/slave SPI serial interface
– Byte-oriented 2-wire serial interface (Philips I
2
C compatible)
– Programmable watchdog timer with separate on-chip oscillator
– On-chip analog comparator
– Interrupt and wake-up on pin change
Special microcontroller features
– DebugWIRE on-chip debug system
– Power-on reset and programmable brown-out detection
– Internal calibrated oscillator
– External and internal interrupt sources
– Five sleep modes: Idle, ADC noise reduction, power-save, power-down, and 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:
– 1.8V - 5.5V for Atmel ATmega48V/88V/168V
– 2.7V - 5.5V for Atmel ATmega48/88/168
Temperature range:
– -40
°
C to 85
°
C
Speed grade:
– ATmega48V/88V/168V: 0 - 4MHz @ 1.8V - 5.5V, 0 - 10MHz @ 2.7V - 5.5V
– ATmega48/88/168: 0 - 10MHz @ 2.7V - 5.5V, 0 - 20MHz @ 4.5V - 5.5V
Low power consumption
– Active mode:
250µA at 1MHz, 1.8V
15µA at 32kHz, 1.8V (including oscillator)
– Power-down mode:
0.1µA at 1.8V
•
•
8-bit Atmel
Microcontroller
with 4/8/16K
Bytes In-System
Programmable
Flash
ATmega48/V
ATmega88/V
ATmega168/V
Summary
•
•
•
•
•
•
•
Note:
1. See
“Data Retention” on page 7
for details.
Rev. 2545TS–AVR–05/11
1. Pin configurations
Figure 1-1.
Pinout Atmel ATmega48/88/1682545TS
TQFP Top View
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)
PDIP
(PCINT19/OC2B/INT1) PD3
(PCINT20/XCK/T0) PD4
GND
VCC
GND
VCC
(PCINT6/XTAL1/TOSC1) PB6
(PCINT7/XTAL2/TOSC2) PB7
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
24
23
22
21
20
19
18
17
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
(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
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
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
28 MLF Top View
PD2 (INT0/PCINT18)
PD1 (TXD/PCINT17)
PD0 (RXD/PCINT16)
PC6 (RESET/PCINT14)
PC5 (ADC5/SCL/PCINT13)
PC4 (ADC4/SDA/PCINT12)
PC3 (ADC3/PCINT11)
32 MLF Top View
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
31
30
29
28
27
26
25
28
27
26
25
24
23
22
(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
21
20
19
18
17
16
15
PC2 (ADC2/PCINT10)
PC1 (ADC1/PCINT9)
PC0 (ADC0/PCINT8)
GND
AREF
AVCC
PB5 (SCK/PCINT5)
(PCINT19/OC2B/INT1) PD3
(PCINT20/XCK/T0) PD4
GND
VCC
GND
VCC
(PCINT6/XTAL1/TOSC1) PB6
(PCINT7/XTAL2/TOSC2) PB7
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
24
23
22
21
20
19
18
17
PC1 (ADC1/PCINT9)
PC0 (ADC0/PCINT8)
ADC7
GND
AREF
ADC6
AVCC
PB5 (SCK/PCINT5)
(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
NOTE: Bottom pad should be soldered to ground.
NOTE: Bottom pad should be soldered to ground.
2
ATmega48/88/168
2545TS–AVR–05/11
(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
ATmega48/88/168
1.1
1.1.1
Pin descriptions
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 tri-stated 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 Oscil-
lator 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
77
and
“System clock and clock options” on page 26.
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 tri-stated 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 char-
acteristics 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 28-3 on page 306.
Shorter pulses are not guaran-
teed to generate a Reset.
The various special features of Port C are elaborated in
“Alternate functions of port C” on page
80.
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
3
2545TS–AVR–05/11
resistors are activated. The Port D pins are tri-stated 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
83.
1.1.7
AV
CC
AV
CC
is the supply voltage pin for the A/D Converter, PC3:0, and ADC7:6. It should be externally
connected to V
CC
, even if the ADC is not used. If the ADC is used, it should be connected to V
CC
through a low-pass filter. Note that PC6..4 use digital supply voltage, V
CC
.
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.
4
ATmega48/88/168
2545TS–AVR–05/11
ATmega48/88/168
2. Overview
The Atmel ATmega48/88/168 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
ATmega48/88/168 achieves throughputs approaching 1 MIPS per MHz allowing the system
designer to optimize power consumption versus processing speed.
2.1
Block diagram
Figure 2-1.
Block Diagram
GND
VCC
Watchdog
timer
Watchdog
oscillator
Power
supervision
POR / BOD &
RESET
debugWIRE
PROGRAM
LOGIC
Oscillator
circuits /
clock
generation
Flash
SRAM
CPU
EEPROM
AVCC
AREF
GND
8bit T/C 0
16bit T/C 1
A/D conv.
2
DATABUS
8bit T/C 2
Analog
comp.
Internal
bandgap
6
USART 0
SPI
TWI
PORT D (8)
PORT B (8)
PORT C (7)
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
5
2545TS–AVR–05/11