49          unsigned int get_crc_16( unsigned int crc, unsigned char *buf, int size )
   \                     get_crc_16:
     50          {
   \   00000000   2E1B                       MOV     R1,R27
   \   00000002   2F6A                       MOV     R22,R26
   \   00000004   01D9                       MOVW    R27 : R26,R19 : R18
   \   00000006   C00C                       RJMP    ??get_crc_16_0
     51          while (size--) {
     52           crc = (crc >> 8) ^ crc_16_tab[ (crc ^ *buf++) & 0xff ];
   \                     ??get_crc_16_1:
   \   00000008   2F71                       MOV     R23,R17
   \   0000000A   912D                       LD      R18,X+
   \   0000000C   2720                       EOR     R18,R16
   \   0000000E   E030                       LDI     R19,0
   \   00000010   0F22                       LSL     R18
   \   00000012   1F33                       ROL     R19
   \   00000014   01F9                       MOVW    R31 : R30,R19 : R18
   \   00000016   ....                       SUBI    R30,LOW((-(crc_16_tab) & 0xFFFF))
   \   00000018   ....                       SBCI    R31,(-(crc_16_tab) & 0xFFFF) >> 8
   \   0000001A   8100                       LD      R16,Z
   \   0000001C   8111                       LDD     R17,Z+1
   \   0000001E   2707                       EOR     R16,R23
     53          }
   \                     ??get_crc_16_0:
   \   00000020   019A                       MOVW    R19 : R18,R21 : R20
   \   00000022   5041                       SUBI    R20,1
   \   00000024   4050                       SBCI    R21,0
   \   00000026   2B23                       OR      R18,R19
   \   00000028   F779                       BRNE    ??get_crc_16_1
     54          return crc;
   \   0000002A   2FA6                       MOV     R26,R22
   \   0000002C   2DB1                       MOV     R27,R1
   \   0000002E   9508                       RET
     55          }