Bit Shifter

Description:

Logical Shifter:

• fills the empty space with 0
• Shift left: A >> 2
• Shift right: A << 2

Arithmetic Shifter:

• Fill the empty space with the most MSB
• Shift right: 11001 >> 2 = 11110
• shift right logical: fill in the left most with sign bit/MSB of the old value
  • In two’s complement, if it negative, it keeps the same value by adding 1; otherwise, add 0 in front dont change
• shift left: 11001 << 2 = 00100
  • add 0 from the back

Rotator Shifter:

• Rotate like a queue
  • 
• The selector decides how many bits are shifted and which bit to replace it
• Can be used as multiplier and divider