Abstract: A programmable logic integrated circuit device has logic modules with some inputs that are optimized for speed (to enhance the speed-performance of the logic modules). For example, some of the inputs may be programmably swappable within a logic module so that a speed-critical input signal can be more easily routed to a faster part of the logic module circuitry. Alternatively or in addition, drivers may be added to the logic module circuitry to improve the speed performance of some of the inputs to the logic module. The logic module may be provided with enhanced “lonely register” circuitry which allows the lonely register output signal to be fed back for use as an input to the combinatorial logic of the logic module. The registers in multiple logic modules may be directly chained to one another in a series.