Flash memory is in range 8...256kB;

RAM is in range 1...4kB;

EEPROM is from 512B to 4kB;

SPI interface;

JTAG programming and debugging interface;

Self programming capability (boot-loading);

4 types of clocking;

Power down modes;

BOD - Brown Out Detecting;

Up to 27 sources of interrupts;

Hardware multiplier;

8 bit and 16 bit timers;

WDT – Watch Dog Timer;

Up to 3 channel PWM generation;

Analog comparator;

10 bit ADC;

UART and USART;

I2C or TWI interface.

Working frequencies up to 20MHz.

ATmega48 4K byte self-programming Flash Program Memory, 512 byte SRAM, 256 Byte EEPROM, 8 Channel 10-bit A/D-converter(TQFP/MLF). debugWIRE On-chip Debug System. Up to 20 MIPS throughput at 20 MHz.
8Kbyte version: ATmega88
16Kbyte version: ATmega168
Automotive Versions:ATmega48 Auto, ATmega88 Auto, ATmega168 Auto

ATmega8 8-Kbyte self-programming Flash Program Memory, 1-Kbyte SRAM, 512 Byte EEPROM, 6 or 8 Channel 10-bit A/D-converter. Up to 16 MIPS throughput at 16 Mhz. 2.7 - 5.5 Volt operation.

ATmega88 8K Byte self-programming Flash Program Memory, 1K Byte SRAM, 512 Bytes EEPROM, 8 Channel 10-bit A/D-converter(TQFP/MLF). debugWIRE On-chip Debug System. Up to 20 MIPS throughput at 20 MHz.
4Kbyte version: ATmega48
16Kbyte version: ATmega168
Automotive Versions:ATmega48 Auto, ATmega88 Auto, ATmega168 Auto

ATmega8515 8-Kbyte self-programming Flash Program Memory, 544 Byte internal + up to 64 Kbyte external SRAM, 512 Byte EEPROM. Up to 16 MIPS throughput at 16 Mhz. 2.7 - 5.5 Volt operation.

ATmega8535 8-Kbyte self-programming Flash Program Memory, 544 Byte SRAM, 512 Byte EEPROM, 8-channel 10-bit A/D Converter. Up to 16 MIPS throughput at 16 MHz. 2.7 - 5.5 Volt operation.

ATmega16 16-Kbyte self-programming Flash Program Memory, 1-Kbyte SRAM, 512 Byte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 Mhz. 2.7 - 5.5 Volt operation.

ATmega162 16-Kbyte self-programming Flash Program Memory, 1-Kbyte SRAM, 512 Byte EEPROM, JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt operation.

ATmega165 16-Kbyte self-programming Flash Program Memory, 1-Kbyte SRAM, 512 Byte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt operation.

ATmega165P picoPower technology AVR Microcontroller.
16-Kbyte self-programming Flash Program Memory, 1-Kbyte SRAM, 512 Byte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt operation.

ATmega168 16K Byte self-programming Flash Program Memory, 1K Byte SRAM, 512 Bytes EEPROM, 8 Channel 10-bit A/D-converter(TQFP/MLF). debugWIRE On-chip Debug System. Up to 20 MIPS throughput at 20 MHz.
4Kbyte version: ATmega48
8Kbyte version: ATmega88
Automotive Versions:ATmega48 Auto, ATmega88 Auto, ATmega168 Auto

ATmega32 32-Kbyte self-programming Flash Program Memory, 2-Kbyte SRAM, 1-Kbyte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 Mhz. 2.7 - 5.5 Volt operation.

ATmega325 32-Kbyte self-programming Flash Program Memory, 2-Kbyte SRAM, 1-KByte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt Operation.
100-pin version: ATmega3250
64KB/64-pin version: ATmega645
64KB/100-pin version: ATmega6450

ATmega3250 32-Kbyte self-programming Flash Program Memory, 2-Kbyte SRAM, 1-KByte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt Operation.
64-pin version: ATmega325
64KB/64-pin version: ATmega645
64KB/100-pin version: ATmega6450

ATmega644 64-Kbyte self-programming Flash Program Memory, 4-Kbyte SRAM, 2-KByte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 20 MIPS throughput at 20 MHz. 1.8 - 5.5 Volt Operation.

ATmega64 64-Kbyte self-programming Flash Program Memory, 4-Kbyte SRAM, 2-Kbyte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 Mhz. 2.7 - 5.5 Volt operation.

ATmega645 64-Kbyte self-programming Flash Program Memory, 4-Kbyte SRAM, 2-KByte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt Operation.
100-pin version: ATmega6450
32KB/64-pin version: ATmega325
32KB/100-pin version: ATmega3250

ATmega6450 64-Kbyte self-programming Flash Program Memory, 4-Kbyte SRAM, 2-KByte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt Operation.
64-pin version: ATmega645
32KB/64-pin version: ATmega325
32KB/100-pin version: ATmega3250

ATmega640 64-Kbyte self-programming Flash Program Memory, 8-Kbyte SRAM, 4-KByte EEPROM, 16 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt Operation.
128KB/64-pin version: ATmega1281
128KB/100-pin version: ATmega1280
256KB/64-pin version: ATmega2561
256KB/100-pin version: Atmega2560

ATmega128 128-Kbyte self-programming Flash Program Memory, 4-Kbyte SRAM, 4-Kbyte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 2.7 - 5.5 Volt operation.

ATmega1281 128-Kbyte self-programming Flash Program Memory, 8-Kbyte SRAM, 4-KByte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt Operation.
64KB/100-pin version: ATmega640
128KB/100-pin version: ATmega1280
256KB/64-pin version: ATmega2561
256KB/100-pin version: Atmega2560

ATmega1280 128-Kbyte self-programming Flash Program Memory, 8-Kbyte SRAM, 4-KByte EEPROM, 16 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt Operation.
64KB/100-pin version: ATmega640
128KB/64-pin version: ATmega1281
256KB/64-pin version: ATmega2561
256KB/100-pin version: Atmega2560

ATmega2561 256-Kbyte self-programming Flash Program Memory, 8-Kbyte SRAM, 4-KByte EEPROM, 8 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt Operation.
64KB/100-pin version: ATmega640
128KB/64-pin version: ATmega1281
128KB/100-pin version: ATmega1280
256KB/100-pin version: Atmega2560

ATmega2560 256-Kbyte self-programming Flash Program Memory, 8-Kbyte SRAM, 4-KByte EEPROM, 16 Channel 10-bit A/D-converter. JTAG interface for on-chip-debug. Up to 16 MIPS throughput at 16 MHz. 1.8 - 5.5 Volt Operation.
64KB/100-pin version: ATmega640
128KB/64-pin version: ATmega1281
128KB/100-pin version: ATmega1280
256KB/64-pin version: ATmega2561