Fixed Point Division Device And Vector Alu&shifter Design

As the developement of communication technology, 3G is used widely, and 4G is researched hotly. This is a challenge for DSP, and requires DSP performance more. On the one hand, DSP is required for higher Data throughput. On the other hand, the DSP power consumed is limited, as the specialty of mobile device.It is a good idea to adopt vector processing unit (VPU). Jump instruction, Branch instructon and other control instructions are processed by scalar processing unit (SPU). And VPU only deal with volumes of parallel data.There are two important components in VPU: Arithmetic Logical Unit (ALU) & Shifter. As the structure of single instruction multiple data (SIMD), ALU and Shifter can increase data throughput both.The paper using nowaday technology advances two SIMD structure.This two structure used by ALU and Shifter make data work harmonious. In SPU, fixed point divider can decrease division operation time obviously.This paper analyses operation demand for LTE, and compares serial typical DSP available for LTE. Then the paper brings SIMD ALU, SIMD shifter, fixed divider for LTE and image processing.The SIMD ALU has four SIMD mode: one 40 bit ALU processing, one 32 bit ALU processing, two 16 bit ALU processing, four 8 bit ALU processing. Using 8 bit ALU as basic unit, SIMD ALU controls carry signal to support SIMD mode.The SIMD SHIFTER has four SIMD mode: one 40 bit shifting, one 32 bit shifting, two 16 bit shifting, four 8 bit shifting. In addition, there are logic shifting left, logic shifting right, arithmetic shifting left and arithmetic shifting right. The SHIFTER makes us of 40 bit shifter as kernel, and add many shifting control structure to limit special data shifting.The paper bring a fixed point division arithmetic and hardware structure correspondingly. In divide processing, shifting and subtracting operation is needed. As the characteristic of binary system, shifting and subtractiong operation can be decrease sharply in divide processing. Separating arithmetic divider jumps processing when the bit of quotient is 0.Finally the paper gives the verification medod, and the result of ALU, Shifter and fixed point divider. All of them are proved to be.well designed.