I have doubt in CPLD and FPGA
praveen, you comeup with a doubt that every basic learner of PLDs wants to know
1. what ever you design in cpld, the same can be applied to FPGA and vice versa.
2. There is a basic difference in its architecture. CPLD is based on macrocells ans FPGA is based on CLBs. As a result you can use CPLD for low to medium level design and FPGA is used for Medium to high level design.
Example: If you want to implement 32 bit microprocessor it is you have to choose FPGA instead of CPLD for its complexity.
CPLDs have a faster input-to-output timings than FPGAs so it can be better suited for microprocessor decoder logic.