avr2
     ``Classic'' devices with up to 8 KiB of program memory.

     MCU = at90c8534, at90s2313, at90s2323, at90s2333, at90s2343, at90s4414, at90s4433, at90s4434, at90s8515, at90s8535, attiny22, attiny26.

avr25
     ``Classic'' devices with up to 8 KiB of program memory and with the MOVW instruction.

     MCU = at86rf401, ata6289, attiny13, attiny13a, attiny2313, attiny2313a, attiny24, attiny24a, attiny25, attiny261, attiny261a, attiny4313, attiny43u, attiny44, attiny44a, attiny45, attiny461, attiny461a, attiny48, attiny84, attiny84a, attiny85, attiny861, attiny861a, attiny87, attiny88.

avr3
     ``Classic'' devices with 16 KiB up to 64 KiB of  program memory.

     MCU = at43usb355, at76c711.

avr31
     ``Classic'' devices with 128 KiB of program memory.

     MCU = at43usb320, atmega103.

avr35
     ``Classic'' devices with 16 KiB up to 64 KiB of program memory and with the MOVW instruction.

     MCU = at90usb162, at90usb82, atmega16u2, atmega32u2, atmega8u2, attiny167.

avr4
     ``Enhanced'' devices with up to 8 KiB of program memory.

     MCU = at90pwm1, at90pwm2, at90pwm2b, at90pwm3, at90pwm3b, at90pwm81, atmega48, atmega48a, atmega48p, atmega8, atmega8515, atmega8535, atmega88, atmega88a, atmega88p, atmega88pa, atmega8hva.

avr5
     ``Enhanced'' devices with 16 KiB up to 64 KiB of program memory.

     MCU = at90can32, at90can64, at90pwm216, at90pwm316, at90scr100, at90usb646, at90usb647, at94k, atmega16, atmega161, atmega162, atmega163, atmega164a, atmega164p, atmega165, atmega165a, atmega165p, atmega168, atmega168a, atmega168p, atmega169, atmega169a, atmega169p, atmega169pa, atmega16a, atmega16hva, atmega16hva2, atmega16hvb, atmega16m1, atmega16u4, atmega32, atmega323, atmega324a, atmega324p, atmega324pa, atmega325, atmega3250, atmega3250a, atmega3250p, atmega325a, atmega325p, atmega328, atmega328p, atmega329, atmega3290, atmega3290a, atmega3290p, atmega329a, atmega329p, atmega329pa, atmega32c1, atmega32hvb, atmega32m1, atmega32u4, atmega32u6, atmega406, atmega64, atmega640, atmega644, atmega644a, atmega644p, atmega644pa, atmega645, atmega6450, atmega6450a, atmega6450p, atmega645a, atmega645p, atmega649, atmega6490, atmega649a, atmega649p, atmega64c1, atmega64hve, atmega64m1, m3000.

avr51
     ``Enhanced'' devices with 128 KiB of program memory.

     MCU = at90can128, at90usb1286, at90usb1287, atmega128, atmega1280, atmega1281, atmega1284p, atmega128rfa1.

avr6
     ``Enhanced'' devices with 3-byte PC, i.e. with more than 128 KiB of program memory.

     MCU = atmega2560, atmega2561.

avrxmega2
     ``XMEGA'' devices with more than 8 KiB and up to 64 KiB of program memory.

     MCU = atxmega16a4, atxmega16d4, atxmega16x1, atxmega32a4, atxmega32d4, atxmega32x1.

avrxmega4
     ``XMEGA'' devices with more than 64 KiB and up to 128 KiB of program memory.

     MCU = atxmega64a3, atxmega64d3.

avrxmega5
     ``XMEGA'' devices with more than 64 KiB and up to 128 KiB of program memory and more than 64 KiB of RAM.

     MCU = atxmega64a1, atxmega64a1u.

avrxmega6
     ``XMEGA'' devices with more than 128 KiB of program memory.

     MCU = atxmega128a3, atxmega128d3, atxmega192a3, atxmega192d3, atxmega256a3, atxmega256a3b, atxmega256a3bu, atxmega256d3.

avrxmega7
     ``XMEGA'' devices with more than 128 KiB of program memory and more than 64 KiB of RAM.

     MCU = atxmega128a1, atxmega128a1u.

avr1
     This ISA is implemented by the minimal AVR core and supported for assembler only.

     MCU = at90s1200, attiny11, attiny12, attiny15, attiny28.