基于32位超标量处理器的保留站设计

摘要

该保留站根据超标量处理器中寄存器重命名的原理，将从数据寄存器或ALU单元送来的数据临时存储在保留站的数据位，当两个数据位的数据都准备好时，则发射存储在保留站中的指令给ALU单元进行运算。文章的设计中，增加了从ALU单元接受数据的结构，使保留站可以判断数据的来源，以及是否使用ALU单元送来的数据。当ALU单元运算完成时，数据可以在下一个时钟周期前送至对应的保留站。与从重排序缓存（ROB）中读取数据相比较，这将减少保留站获取数据的时间。%The reservation station will temporarily store the data sent by data register or the ALU unit according to superscalar processor register renaming principle. When the data in two data bits is ready, the instructions stored in reservation station will be sent to ALU unit to calculate. In this design, a structure is added to receive data from ALU unit. It can judge the source of the data and whether the data sent by ALU unit will be used. When the ALU unit operation is complete, the data can be sent to corresponding reservation station before the next clock cycle. Compared to read data from the reordering buffer (ROB), this will reduce the time that reservation station need to get the data.