Preset and reset circuitry for programmable logic device memory elements

摘要

Integrated circuits such as programmable logic device integrated circuits have arrays of memory elements into which configuration data is loaded. The memory elements are formed form a pair of independently-powered cross-coupled inverters. Control circuitry generates a first inverter power supply signal and a second inverter power supply signal. The first and second inverter power supply signals are distributed to the inverters in the memory elements using pairs of inverter power distribution paths. When it is desired to reset the memory elements, the control circuitry takes the second power supply signal high before the first power supply signal. When it is desired to preset the memory elements, the control circuitry takes the second power supply high after the first power supply signal.