PLDs providing reduced delays in cascade chain circuits

摘要

The present invention provides a Programmable Logic Device (PLD) incorporating a two-input multiplexer for providing a Cascade Logic output and having a Cascade Logic input coupled to a select line. A two-input multiplexer provides the desired configurable Cascade Logic function, and an initialization circuit sets the initial value for the Cascade logic under control of an initialization configuration bit. The multiplexer that provides the Cascade Logic output also provides the desired configurable Cascade Logic function using the Look-up table (LUT) and configuration bits.