# Modify SDHC power management states Modify the following SDHC power management states to optimize power management. SDHC power management states | State | Description | | --- | --- | | Runtime suspend or resume |
The SD card enters the runtime suspend state after 50 ms of inactivity.
Resume occurs with the next SD card operation. This state is enabled by default and is not configurable.
The eMMC transitions to the runtime suspend state after 50 milliseconds of inactivity. It resumes with the next I/O operation. This feature is always enabled and cannot be configured.
The SD card enters system suspend state with the suspend event.
SD card system resume state occurs with the system resume event.
This state is enabled by default and is not configurable.
The eMMC enters system suspend mode upon receiving a suspend event and resumes operation with a system resume event. This functionality is always enabled and cannot be configured.