Design of Variable Width Barrel Shifter for High Speed Processor Architecture

摘要

Microprocessor is the brain of the computer. It works as the Central Processing Unit of the computer. It contains Arithmetic Logical Unit (ALU) that performs the arithmetic operations such as Addition, Subtraction, Multiplication and Division. It also performs the Logical operations such as AND, NAND, OR, NOR, EXOR, EXNOR and NOT. It also contains register file to store the operand in load/store instructions in RISC Processor Architecture. Control Unit genetares the control signals that synchronize the operation of the processor which tells the microarchitecture which operation is done at which time. Now during the multiplication partial product is shifted and added. So shifter is an important part of the processor architecture. Barrel Shifter is an important combinational logic block. It was incorporated in 386 processor and is also used in microcontroller design. Intel has since moved to software implemented shifters in the Pentium 4 Processor Architecture but AMD still uses it. Here the design of the variable width barrel shifter is presented in which we can shift 4bit, 8bit, 16bit, and 32bit and maximum 64bit partial product during multiplication. Functionality is check using Modelsim 6.4a.Now to generate the gate level netlist Xilinx ISE 9.2i is used.