Patent attributes
A programmable logic device (PLD) having a programmable routing structure that employs non-static memory cells, such as dynamic random access memory (DRAM) cells, to control configurable circuit elements, such as pass-transistors and/or MUXes. In a representative embodiment, each DRAM cell is connected to its corresponding configurable circuit element using a buffer adapted to stabilize the output voltage generated by the cell and offset the effect of charge leakage from the cell capacitor. In addition, refresh circuitry associated with the DRAM cell periodically restores the charge in the cell capacitor using a refresh operation that is performed in the background, without disturbing the user functions of the PLD. Advantageously, a relatively large capacitance associated with a DRAM cell makes a PLD of the invention less susceptible to soft errors than a prior-art PLD that relies on SRAM cells for configuration control of its routing structure.
