Overview：

 

    The shifter performs bitwise shifting for 16-bit, 32-bit or 40-bit inputs and yields 16-bit, 32-bit, or 40-bit outputs.

 

    Functions

• Arithmetic Shift:  

    The Arithmetic Shift instruction shifts a registered number a specified distance and direction while preserving the sign of the original number.

    The sign bit value back-fills the left-most bit positions vacated by the arithmetic right shift.

• Logical Shift:  

    The Logical Shift instruction logically shifts a registered number a specified distance and direction.  

    Logical shifts discard any bits shifted out of the register and backfill vacated bits with zeros.

 

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