The Cpld Architecture Research

PLD (Programmable Logic Device) has been the most-commonly-used device in the digital circuit design since its invention about 30 years ago. Now most of CPLD/FPGA architectures are based on the product-term structure or the look-up-table structure. In general, the PLDs based on the former are called CPLDs, and the ones based on the latter are called FPGAs.After my analyzing and researching CPLD architectures of each company, this subject aims to put forward a PLD architecture based on the product-term structure, and accomplishes to design a product of CPLD - HWD1472 by using this architecture. Then according to the accomplishment of HWD1472 designing, the design of CPLD family - HWD1400 family– will achieve.At the same time, this subject compares the devices of XC9500 family with that of XC9500XL family and XC9500XV family, then analyzes the feasibility, which using XC9500 family devices to implement the designing of XC9500XL and XC9500XV families by the way of process transplanting. Moreover, the subject raises a compatibility solution to replacing MAX7000S and ispLSI1000 devices with HWD1400 devices.I am responsible for the general circuit design and simulation, and the general design of the technology transplanting and the compatibility solution.This paper first briefly introduces the present status of PLDs and developing course of PLDs'architectures, and gives a summary of the architectures of Xilinx XC9500, Altera MAX7000S and Lattice ispLSI1000 devices. Then the paper elaborates on the processes of implementing to design HWD1472 and HWD1400 family devices, and discusses the feasibility of process transplanting. Finally, the paper presents a compatibility solution to CPLD replacements in detail.The research on CPLD architectures vie this subject is helpful to our CPLD development, and could point out the CPLD progress direction. It also accomplishes the technological reserve for our company aiming at the largest CPLD supplier in China.