In avr-instruction-set von Atmel stehen keine Opcodes, da sind nur die Mnemonics aufgeführt. FF FF ist jedenfalls keine gültige Instruktion. Keine Ahnung was sie macht oder und woher Chertykov seine Info hat...

Zitat Zitat von Denis Chertykov (in <binutils>/include/opcode/avr.h)
Code:
/* Opcode table for the Atmel AVR micro controllers.

   Remaining undefined opcodes (1699 total - some of them might work
   as normal instructions if not all of the bits are decoded):

    0x0001...0x00ff    (255) (known to be decoded as `nop' by the old core)
   "100100xxxxxxx011"  (128) 0x9[0-3][0-9a-f][3b]
   "100100xxxxxx1000"   (64) 0x9[0-3][0-9a-f]8
   "1001001xxxxx01xx"  (128) 0x9[23][0-9a-f][4-7]
   "1001010xxxxx0100"   (32) 0x9[45][0-9a-f]4
   "1001010x001x1001"    (4) 0x9[45][23]9
   "1001010x01xx1001"    (8) 0x9[45][4-7]9
   "1001010x1xxx1001"   (16) 0x9[45][8-9a-f]9
   "1001010xxxxx1011"   (32) 0x9[45][0-9a-f]b
   "10010101001x1000"    (2) 0x95[23]8
   "1001010101xx1000"    (4) 0x95[4-7]8
   "1001010110111000"    (1) 0x95b8
   "1001010111111000"    (1) 0x95f8 (`espm' removed in databook update)
   "11111xxxxxxx1xxx" (1024) 0xf[8-9a-f][0-9a-f][8-9a-f]
 */