复杂指令集快速译码设计

【作者】 易海峰；

【导师】 高德远；

【作者基本信息】 西北工业大学 ， 计算机系统结构， 2005， 硕士

【摘要】 CISC结构的微处理器指令功能复杂,指令长度不固定。设计合理的译码器能加快指令译码速度,提高指令流水效率,从而能有效提高处理器性能。 本文结合“十五”预研课题,完成了32位CISC微处理器“龙腾C1”中的指令译码器的设计与验证工作。“龙腾C1”微处理器在指令集上与Intel486DX2微处理器兼容,己作为微处理器IP核应用于PC104工控系统SOC芯片“龙腾S1”中。 本文的主要研究工作包括: 1.分析了486微处理器的结构,参与完成了“龙腾C1”处理器体系结构的设计。 2.对“龙腾C1”指令集进行了深入的分析,设计了一种基本译码器。 3.对486指令系统的指令长度、指令的使用频率、指令的编码特点进行了深入分析,提出了加快译码速度的设计方案。 4.实现了“龙腾C1”微处理器的快速译码器,完成了模块级和芯片级的功能验证。 5.研究了Pentium处理器译码器的结构,分析了它的设计难点,为设计Pentium兼容微处理器的译码器提出了一些设计思路。 以“龙腾C1”为核心的“龙腾S1”芯片已经在FPGA验证平台上,完成了功能验证,可以运行DOS操作系统和DOS下的应用程序。本论文的研究成果对顺利完成“十五”国防预研项目和“龙腾S1”的投片奠定了基础。更多还原

【Abstract】 CISC instruction is complex in function and variable in length. So research on how to design a suitable decoder can speedup the instruction decoding, enhance the efficiency of the instruction pipeline, and consequently improve the performance of microprocessor effectively.I was working on the "National Advanced Research Project", during which I finished the design and verification of the instruction decoder in "Longtium C1"— a 32bit CISC microprocessor. "Longtium C1" is compatible with Intel486DX2 in instruction set and also has been used in "Longtium S1" industrial control system as the microprocessor IP core.The research work of this paper mainly includes:1. Studied the architecture of Intel486DX2, took part in and finished the design of the architecture of "Longtium Cl".2. Deeply studied the principle of the "Longtium Cl" instruction system and designed a basic decoder.3. Deeply studied the length of the 486 instructions, frequency in using of the instructions, the character of the instruction encoder. Brought out the design idea to speedup decoding.4. Designed and implemented express decoder. Completed the verification of express decoder in module level and chip level.5. Studied the decoder in Pentium microprocessor and analyzed the difficulty of the design, presented some ideas for designing the decoder of the microprocessor compatible with Pentium processor.The "Longtium S1" with "Longtium C1" core had been verified in FPGA verification platform on which DOS and some application programes can run. All the work presented in this paper established a foundation for the accomplishment of the pre-research project, and assured the tape-out of "Longtium S1".更多还原