POWER CONTROL USING GLOBAL CONTROL SIGNAL TO SELECTED CIRCUITRY IN A PROGRAMMABLE INTEGRATED CIRCUIT

When a first sub-circuit of a programmable integrated circuit (“IC”) is to be deactivated, a global write enable (GWE) signal is deasserted. In response to deassertion of the GWE signal and a first memory cell associated with the first sub-circuit being in a first state, flip-flops in the first sub-circuit are disabled from changing state. In response to memory cells associated with sub-circuits other than the first sub-circuit being in a second state, flip-flops in the other sub-circuits are enabled to change state. When the first sub-circuit is to be activated, the GWE signal is asserted. Logic implemented by the first sub-circuit is preserved between the deasserting and the asserting of the GWE signal. In response to assertion of the GWE signal and the first memory cell associated with the first sub-circuit being in the first state, flip-flops in the first sub-circuit are enabled to change state.