US Patent 7911229 Programmable signal routing systems having low static leakage

Parasitic static leakage current through input terminals of bus-accessing multiplexers is minimized by automatically forcing as many as practical of the bus lines into a high impedance state where all drivers of the lines are in a high impedance output state. Thus parasitic current sinking or current sourcing leakage paths through the bus-accessing multiplexers are cut off. The method is of particular utility in a low power FPGA that desirable has low static current leakage when in a static state.