Programmable integrated circuits with in-operation reconfiguration capability

Integrated circuits may include partial reconfiguration (PR) circuitry for reconfiguring only a portion of a memory array. In some applications, partial reconfiguration may be performed during user mode. During partial reconfiguration, write assist techniques such as varying the power supply voltage may be applied to help increase write margin, but doing so can potentially affect the performance of in-operation pass gates that are being controlled by the memory array during user mode. In one suitable arrangement, ground power supply voltage write assist techniques may be implemented on memory cells that include p-channel access transistors and that are used to control n-channel pass transistors. In another suitable arrangement, positive power supply voltage write assist techniques may be implemented on memory cells that include n-channel access transistors and that are used to control p-channel pass transistors.