SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
CAL supports a IDLE protocol interface. It is used to ensure that the CAL clock / power can only be cut where there are no pending transactions. It is also used to ensure that CAL generates no more traffic before gating the functional clock. The PRCM sends an IDLE request to CAL when the software requests CAL shutdown.
When CAL receives an IDLE request, it performs the following actions:
On CAL level the IDLE protocol configuration is controlled via CAL_HL_SYSCONFIG[3:2] IDLEMODE register bit-field. For more information on CAL clock and power management on device level, see CD_CAM Clock Domain and PD_CAM Description in Power, Reset, and Clock Management.
For more information on CSI2 PHY power management, refer to Section 10.4.5.2, CSI2 PHY Configuration.