created: 07/08/01; revisions: 02/13/03

# CHAPTER 12 — Shift Instructions and Logic Instructions

It often happens that a bit pattern must be moved left or right within a register. The instructions that do this are the shift instructions.

#### Chapter Topics:

- Logical shift instructions (`sll` and `srl`).
- No-op as a shift instruction.
- Bitwise logic instructions (`or`, `and`, `xor`, `nor`).
- NOT as a NOR operation.
- MOVE as an OR operation.
- Example program: instruction assembly.

### QUESTION 1:

(Review:) If a bit pattern that represents an integer N (say `0110 0001`) is shifted left by one bit (to `1100 0010`) what integer does the new bit pattern represent?