Research Of CPLD-Based SCM Structure Designing

Since it was invented, single-chip microcomputer (SCM) has been applied in many fields widely because it is cabinet, flexible and it's low cost, powerful controlling and easily manufacturing. But with the coming of the communication age, the disadvantage of the traditional SCM was discovered because of its connatural structure defect. Its speed, scale and performance can't meet more and more requirements of the users. So the development and upgrading of SCM is faced with new challenges. The complex programmable logic device (CPLD) breaks a new path for the reconformation of SCM. Based on CPLD and MAX+PLUSâ…¡ a fundamental SCM system was designed. This thesis mainly expatiated a method that uses CPLD to design SCM. An 8 bits SCM was designed with VHSIC hardware description language (VHDL). According to the designing course, firstly, SCM was divided into different modules that the function was single. Secondly, every module was described with VHDL. Then all programs were compiled and simulated. Finally, programs were downloaded to the CPLD. After the designing was finished, the instruction system and operating scheduling were given. Then an assembly program was composed to test and verify the function of the SCM.The thesis used EP1K100QC208-2, the ACEX 1K CPLD of Altera to form the ultimate hardware circuit. It is SRAM-based CPLD. Because of the volatility of the SRAM, CPLD can't store the configuration data. So the configuration method was studied and a configuring board for the 208-pins CPLD was developed. The CPLD can be configured with downloading cable directly or configuration device on this board.As a result, the method that uses CPLD to form the structure of SCM is feasible. And CPLD-based SCM accords with the development trend.