20.1 Overview

The Power Manager (PM) controls the sleep modes and the power domain gating of the device.

Various sleep modes are provided in order to fit power consumption requirements. This enables the PM to stop unused modules in order to save power. In active mode, the CPU is executing application code. When the device enters a sleep mode, program execution is stopped and some modules and clock domains are automatically switched off by the PM according to the sleep mode. The application code decides which sleep mode to enter and when. Interrupts from enabled peripherals and all enabled reset sources can restore the device from a sleep mode to active mode.

Performance level technique consists of adjusting the regulator output voltage to reduce power consumption. The user can select on the fly the performance level configuration which best suits the application.

The power domain gating technique enables the PM to turn off unused power domain supplies individually, while keeping others powered up. Based on activity monitoring, power domain gating is managed automatically by hardware without software intervention. This technique is transparent for the application while minimizing the static consumption. The user can also manually control which power domains will be turned on and off in standby sleep mode.

In backup mode, the PM allows retaining the state of the I/O lines, preventing I/O lines from toggling during wake-up.

The internal state of the logic is retained (retention state) allowing the application context to be kept in non-active states.