The selected mcu core is the pic16c54 , which one kind of the microchip ' s pic16c5x series , this kind of 8 bit series have many merit , it mainly include the wide byte and single cycle , and harvard - double - bus , and risc structure 所选用的mcu核是microchip公司的pic16c5x系列中的16c54 ，该系列8位mcu具有很多的优点，主要体现在宽字节单周期指令、哈佛双总线和risc结构。
Information technology - telecommunications and information exchange between systems - local and metropolitan area networks - specific requirements - part 6 : distributed queue dual bus access method and physical layer specifications contains ansi ieee 802 . 6 - 1990 , 802 . 6d - 1994 , and 802 . 6f - 1994 信息技术.系统间电信和信息交换.局域和城域网.特殊要求.第6部分:分布式队列双总线接入法和物理层规范
As a result of studying , we gain three system time capability parameter of monolayer bus framework and two - double bus framework , data bus utilization , length of the data waiting queue and time of system timed , basing on fixed bc control seasonal repertoire timed petri net and stochastic petri net 研究结果分别得出了单总线和双总线的基于固定主控端周期指令时延petri网的数据总线利用率、等候消息队长、系统延时时间；基于随机petri网的数据总线利用率、等候消息队长、系统延时时间共三个系统时间性能指标。
