| Various aspects of PLDs, ASICs, and FPGAs will be discussed later in more detail. For now, we need only be aware that PLDs are devices whose i nternal architecture is predetermined by the manufacturer, but are created in such a way that they can be configured by engineers in the field to perform a variety of different functions. In comparison to an FPGA, however, these devices contain a relatively limited number of logic gates, and the functions they can be used to implement are much smaller and simpler.
At the other end of the spectrum are ASICs and ASSPs that can contain hundreds of millions of logic gates and can be used to create incredibly large and complex functions. ASICs and ASSPs are based on the same design processes and manufacturing technologies. Both are custom-designed to address a specific application, the only difference being that an ASIC is designed and built to order for use by a specific company, while an ASSP is marketed to multiple customers. |
