3.3.12.5 Barrel Shifter

The barrel shifter can perform up to a 32-bit arithmetic right shift, or up to a 32-bit left shift, in a single cycle. DSP or MCU instructions can use the barrel shifter for multibit shifts.

The shifter requires a signed binary value to determine both the magnitude (number of bits) and direction of the shift operation.

• A positive value shifts the operand right.
• A negative value shifts the operand left.
• A value of ‘0’ does not modify the operand.

The barrel shifter is 72 bits wide to accommodate the width of the accumulators. A 72-bit output result is provided for DSP shift operations, and a 32-bit result is provided for MCU shift operations.

Table 3-7 provides a summary of instructions that use the barrel shifter.