Optimizing CRC16 routine.

[cncmachineguy]

Hi Henrik,
here is the snippit I am testing:

Main:      'DO WHATEVER YOU WANT HERE
tmr1=0
t1con = 1
    For MB_j = 0 to 7                      ' Cycle thru the low byte of the CRC value                      
        If MB_CRC.Bit0 THEN                ' If the LSB is set
            MB_CRC = MB_CRC >> 1           ' We shift CRC on bit to the right....
            MB_CRC = $A001 ^ MB_CRC        ' and EXOR it with out polynomial for MODBUS CRC-16 ($A001)
        ELSE
            MB_CRC = MB_CRC >> 1           ' If the LSB is not set we simply shift CRC one bit to the right.
        ENDIF
    Next                                   ' Next bit in the byte
t1con = 0
stopnow:
goto stopnow

This takes 169 cycles according to TMR1 setup as you see here. I have tried with both $A001 and $1021. Both are the same. Does this fall in line with what you have?

BTW, MPLAB stopwatch reports the same

Next I think I will try out DT's snippet