微处理器保护测试单元PTU的研究

On the Designing of the Protection Test Unit of a Microprocessor

设计拥有我国自主版权的微处理器在国防及民用有着重大意义 ,保护测试单元 PTU是支持微处理器运行于保护模式的重要部件。文中提出了保护测试单元 PTU设计方法 ,建立了保护测试单元的数据通路和控制通路 ,确定了保护测试单元 PTU结构 ,给出了 PTU与控制 ROM,DBUS和其它单元的相互关系。保护测试单元由多个基本构件 CELL组成 ,每个构件 CELL可进行一种测试 ,基于这种测试 ,可确立微处理器内部微程序的转移。最后用 EDA工具 SYNOPSYS对保护测试单元 RTL级的 VHDL描述进行综合与仿真 。

We designed a microprocessor with copyright. We embedded a protection test unit (PTU) in the microprocessor. In this paper, We focus on the design of such a PTU. After analyzing micro instruction flows in protected mode, we put forward a kind of cell group structure for PTU. The structure consists of cells, each cell processes a kind of test and output Boolean value to the controller of micro program to control the branch of micro program. This cell group structure makes it possible to execute microprocessor instructions in protected mode. We use VHDL to describe the design of PTU. Finally, we use a kind of EDA tools——SYNOPSYS, to synthesize and simulate the microprocessor with PTU. Simulation result proves that our design is successful.