A power sequence in a power-delivery (PD) mechanism (interaction between host system components and a charger) and a firmware sequence during power contract negotiation reduces the host system power consumption at or below the pSnkStdby power limit to improve user experience and battery life. The power sequence uses USB Type-C PD protocol and timing specification to implement a synchronous trigger or interrupt and interface mechanism. The synchronous trigger or interrupt and interface mechanism between a PD controller and an embedded controller firmware controls the power consumption dynamically during the boot flow sequence to be less than or equal to pSnkStdby power limit while implementing a predictable boot sequence and optimizing boot time. The power negotiating sequence is also applicable when a source (e.g., a charger) is connected to a SoC host system which is in active state (e.g., S0) and when there is an indication of low battery capacity.