"Microcontroller: fewer op- codes, more
bit handling Instructions"

here what is mean by bit handling mechanism

 

A mechanism that deals with bits? Maybe ANDing, ORing, shifting, toggling, settting or clearing them?

 

My guess is it refers to
BSET, BCLR (bit set and bit clear) and
BRSET and BRCLR, (branch if bit is set, branch if bit is clear) instructions.