Abstract: Various embodiments of methods and systems for hardware-based memory power management (“HMPM”) in a portable computing device (“PCD”) running secure and non-secure execution environments are disclosed. Hardware-based state machines are uniquely associated with, and under the control of, the non-secure execution environment, the secure execution environment and a virtual manager, respectively. The states of the state machines constitute votes by each of the execution environments and the virtual manager to control the power supply state to the memory component, such as a cache memory. The votes are monitored by a digital circuit that, based on a combination logic of the votes, generates an output signal to trigger a power management component to maintain, supply or remove power on a rail associated with the memory component. In this way, the power supply state to the memory component cannot be unilaterally changed by an application running in the non-secure execution environment.