Based On The Structure Of The Altivec Vector Processing Unit

Based on the National Defense Preliminary Research Project ,the author is responsible for the design and implementation of the fixed-point executing unit which is the core of the 32-bit embeded RISC microprocessor "LongtiumR2".On the fully understanding of the "Longtium" architecture ,The author gives a deep study on the AltiVec technology, in order to enhance the processing ability of the multimedia data on the serial processors of Longtium".The research work of this dissertation mainly includes:1. Systematically analyze and research the high performance RISC microprocessor architecture,design the fixed-point executing unit of the "LongtiumR2" .and present the verification method of the unit.2. Based on the design,deeply research the AltiVec technology, including the ISA ,data convention and addressing mode ,etc.All of that is useful for introducing a multimedia processing unit on the architecture of the "Longtium" architecture.3. Combined the AltiVec technology and the superscalar technology ,present the controlpath architecture of the vector unit which will be implemented by AltiVec technology.The vector unit can accept two instructions per cycle,and the instructions can be executed out of order.The controlpath adopts the pipeline structure which has five stages and the instruction scheduling technology is assigned to different stages of the pipeline ,which eases the pressure of the architecture design on the physical design.Finally,through the multimedia benchmark,give a simple performance evaluation of vector unit .The result is that the vector unit can process 1.4 instructions per cycle,which demonstrates the architecture can improve the performance of the vector unit.4. Present the datapath architecture of the vector unit.The ALU of the vector unit can be divided into three parts:VPU,which is responsible for the manipulation of the data elements;VSFU,which is responsible for the simple operations of the fixed-point,including add,shift,subtract,ect;VCFU,which is responsible for the complex operations of the fixed-point,mcluding multiply,sum cross.etc.