Practical Electronic Design for Experimenters

CHAPTER 12Programmable Logic Devices (PLDs)

An alternative to discrete TTL or CMOS logic ICs is a programmable logic device (PLD). This is an integrated circuit containing some prewired logic circuits that can be further programmed to implement your boolean equations or other logic design. These logic circuits use the sum of products (SOPs) format in which the AND gates or the OR gates are programmable, or both. Different methods have been used to program these chips. While these chips greatly reduce the size of a design, some of them have disappeared from the market. The focus instead has been on a larger and more complex PLD called a field programmable gate array (FPGA). The FPGA can implement almost any digital circuit. This chapter summarizes ...