SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The PRCM module controls the power state of the MPU subsystem, whereas the PRCM_MPU controls the power state of each CPU (CPU0 and CPU1). The MPU subsystem requires that the MPU power domain can transition only to a low-power mode when CPU0 and CPU1 are in a lower power mode than is specified in the PM_MPU_PWRSTCTRL register. The power mode of the CPUs is communicated to the PRCM module by the PRCM_MPU through two dedicated internal signals. These two signals specify the lowest power state that the MPU can enter and, if necessary, override the low-power state programmed in the PM_MPU_PWRSTCTRL register.
Table 3-355 lists the low-power modes allowed by the MPU.
MPU Allowed Low-Power Mode | Comment |
---|---|
CSWRET | CPUs are in SR3-APG mode and L1$ is in RETENTION state. |
INACTIVE | CPUs are in SR3-APG mode and L1$ is in ON state, or CPUs are in INACTIVE state. |
ON | CPUs are in ON state. |
If PM_MPU_PWRSTCTRL is programmed to a lower power state than allowed (specified by the two signals), then it is overwritten by the hardware. The valued of the PM_MPU_PWRSTCTRL register is not changed (that is, not overwritten).