Power Management
15-30
15.3.2.2
DPLL Subdomain
DPLL1 is disabled when all of the clock domains using DPLL1 are disabled.
Setting up the IDLDPLL_MPU bit enables DPLL1 to enter the idle mode when
the following conditions are met; otherwise, DPLL1 remains active.
-
DSP is set in the global idle mode.
-
MPU is set in the idle mode (either from request or from wait-for-interrupt).
-
There is no active DMA transaction and there is no activity on the internal
local bus, as indicated by the internal TCLB_EN signal
-
No peripheral post write is queued.
-
The peripheral clocks are stopped.
-
There are no pending interrupts.
15.3.2.3
Peripheral Subdomain
Two clocks feed the MPU peripherals:
-
The clock that is shut off/activated according to the MPU idle mode.
Peripherals connected to this clock cannot request DMA transfers during
the MPU idle mode.
-
The clock that is never shut off (input reference clock)
In either case, the MPU peripheral clocks are directly shut off/activated by the
MPU software.
15.3.3 Traffic Controller Idle Modes
A clock management register, ARM_IDLECT1, controls different clock subdo-
mains (clock enables) during the idle state and allows the user to put different
parts of the traffic controller into idle mode, if desired.
Several different subdomains are defined.
-
System DMA subdomain
To optimize power consumption, the system DMA controller clock
(DMA_CK) can be shut off/activated according to the DMA activity
(provides clock during data transfer only) or it can be shut off only when
MPU goes to idle.