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 8-bit Atmel – 512/1K/1Kbytes internal SRAM – Write/erase cyles: 10,000 flash/100,000 EEPROM Microcontroller – Data retention: 20 years at 85°C/100 years at 25°C(1) – Optional boot code section with independent lock bits with 4/8/16K In-system programming by on-chip boot program True read-while-write operation Bytes In-System – Programming lock for software security • QTouch® library support Programmable – Capacitive touch buttons, sliders and wheels – QTouch and QMatrix acquisition Flash – Up to 64 sense channels • Peripheral features – Two 8-bit timer/counters with separate prescaler and compare mode ATmega48/V – One 16-bit timer/counter with separate prescaler, compare mode, and capture mode – Real time counter with separate oscillator ATmega88/V – Six PWM channels – 8-channel 10-bit ADC in TQFP and QFN/MLF package – 6-channel 10-bit ADC in PDIP Package ATmega168/V – 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 Summary – 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 Note: 1. See “Data retention” on page 8 for details. Rev. 2545US–AVR–11/2015 ATmega48/88/168 1. Pin configurations Figure 1-1. Pinout Atmel ATmega48/88/168. TQFP Top View 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) (PCINT14/RESET) PC6 1 28 PC5 (ADC5/SCL/PCINT13) 32 31 30 29 28 27 26 25 (PCINT16/RXD) PD0 2 27 PC4 (ADC4/SDA/PCINT12) (PCINT17/TXD) PD1 3 26 PC3 (ADC3/PCINT11) (PCINT19/OC2B/INT1) PD3 1 24 PC1 (ADC1/PCINT9) (PCINT18/INT0) PD2 4 25 PC2 (ADC2/PCINT10) (PCINT20/XCK/T0) PD4 2 23 PC0 (ADC0/PCINT8) (PCINT19/OC2B/INT1) PD3 5 24 PC1 (ADC1/PCINT9) GND 3 22 ADC7 (PCINT20/XCK/T0) PD4 6 23 PC0 (ADC0/PCINT8) VCC 4 21 GND VCC 7 22 GND GND 5 20 AREF GND 8 21 AREF VCC 6 19 ADC6 (PCINT6/XTAL1/TOSC1) PB6 9 20 AVCC (PCINT6/XTAL1/TOSC1) PB6 7 18 AVCC (PCINT7/XTAL2/TOSC2) PB7 10 19 PB5 (SCK/PCINT5) (PCINT7/XTAL2/TOSC2) PB7 8 17 PB5 (SCK/PCINT5) (PCINT21/OC0B/T1) PD5 11 18 PB4 (MISO/PCINT4) (PCINT22/OC0A/AIN0) PD6 12 17 PB3 (MOSI/OC2A/PCINT3) 9 10 11 12 13 14 15 16 (PCINT23/AIN1) PD7 13 16 PB2 (SS/OC1B/PCINT2) (PCINT0/CLKO/ICP1) PB0 14 15 PB1 (OC1A/PCINT1) (PCINT4/MISO) PB4 (PCINT1/OC1A) PB1 (PCINT23/AIN1) PD7 (PCINT2/SS/OC1B) PB2 (PCINT21/OC0B/T1) PD5 (PCINT0/CLKO/ICP1) PB0 (PCINT0/CLKO/ICP1) (PCINT3/OC2A/MOSI) PB3 (PCINT22/OC0A/AIN0) PD6 28 MLF Top View 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) PD2 (INT0/PCINT18) PD1 (TXD/PCINT17) PD0 (RXD/PCINT16) PC6 (RESET/PCINT14) PC5 (ADC5/SCL/PCINT13) PC4 (ADC4/SDA/PCINT12) PC3 (ADC3/PCINT11) 32 31 30 29 28 27 26 25 28 27 26 25 24 23 22 (PCINT19/OC2B/INT1) PD3 1 21 PC2 (ADC2/PCINT10) (PCINT19/OC2B/INT1) PD3 1 24 PC1 (ADC1/PCINT9) (PCINT20/XCK/T0) PD4 2 20 PC1 (ADC1/PCINT9) (PCINT20/XCK/T0) PD4 2 23 PC0 (ADC0/PCINT8) VCC 3 19 PC0 (ADC0/PCINT8) GND 3 22 ADC7 GND 4 18 GND VCC 4 21 GND (PCINT6/XTAL1/TOSC1) PB6 5 17 AREF GND 5 20 AREF (PCINT7/XTAL2/TOSC2) PB7 6 16 AVCC VCC 6 19 ADC6 (PCINT21/OC0B/T1) PD5 7 15 PB5 (SCK/PCINT5) (PCINT6/XTAL1/TOSC1) PB6 7 18 AVCC (PCINT7/XTAL2/TOSC2) PB7 8 17 PB5 (SCK/PCINT5) 8 9 10 11 12 13 14 9 10 11 12 13 14 15 16 NOTE: Bottom pad should be soldered to ground. NOTE: Bottom pad should be soldered to ground. (PCINT4/MISO) PB4 (PCINT1/OC1A) PB1 (PCINT23/AIN1) PD7 (PCINT4/MISO) PB4 (PCINT2/SS/OC1B) PB2 (PCINT1/OC1A) PB1 (PCINT23/AIN1) PD7 (PCINT0/CLKO/ICP1) PB0 (PCINT0/CLKO/ICP1) (PCINT3/OC2A/MOSI) PB3 (PCINT22/OC0A/AIN0) PD6 (PCINT2/SS/OC1B) PB2 (PCINT21/OC0B/T1) PD5 (PCINT0/CLKO/ICP1) PB0 (PCINT0/CLKO/ICP1) (PCINT3/OC2A/MOSI) PB3 (PCINT22/OC0A/AIN0) PD6 2 2545US–AVR–11/2015 ATmega48/88/168 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 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 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 83 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 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 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 29-3 on page 314. 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 86. 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 2545US–AVR–11/2015 ATmega48/88/168 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 89. 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. 4 2545US–AVR–11/2015 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.