2. Serial shift registers Draw missing connections to implement various shift registers 1. Shift right: All bits of the register move right by one position, and a new bit value from a serial input is stored in the most significant bit (leftmost flip-flop below). Serial input -02 az 02 a Do ao Serial indino 2. Shift left: All bits of the register move left by one position, and a new bit value from a serial input is stored in the least significant bit (rightmost flip-flow below). Serial output Serial input D2 Q D₂ L P CLK- 3. Circular shift left (also known as rotate left): the output of the leftmost flip-flop feeds back into the rightmost flip-flop. Hence each bit moves left, and the leftmost bit becomes the rightmost bit. – D2 Q2 Di Do at O-

4. Circular shift right (also known as rotate right): the output of the rightmost flip-flop feeds back into the leftmost flip-flop. Hence each bit moves right, and the rightmost bit becomes the leftmost bit. D2 Do oot 5. Logical shift right: The bits in the register are treated as an unsigned number for simply a set of bits). All bits of the register move right towards less significant digits) by one position, and a O is stored in the most significant bit (leftmost flip-flop below). Logical shift right corresponds to division by 2 for unsigned numbers. -D2 0 0 Do at 6. Arithmetic shift left: The register contents are treated as a Z’s complement number, so a O is shifted into the least significant bit (the rightmost flip-flop). Arithmetic shift left corresponds to multiplication by 2 for 2’s complement numbers. Notice that arithmetic and logical shift left are identical. -D2 Q Di at 7. Arithmetic shift right: The register contents are treated as a 2’s complement number, so the sign bit (leftmost flip-flop below) is copied back into itself. Arithmetic shift right corresponds to division by 2 for 2’s complement numbers. DI Q