Power, Reset, and Clock Management
Table 8-3. Module Idle Mode Settings (continued)
Idle Mode Value
Selected Mode
Description
The module acknowledges the idle
request basing its decision on its internal
activity. Namely, the acknowledge signal
is asserted only when all pending
0x2
Smart-idle
transactions, interrupts, or direct memory
access (DMA) requests are processed.
This is the best approach to efficient
system power management.
The module acknowledges the idle
request basing its decision on its internal
wakeup-capable mode activity. Namely,
the acknowledge signal is asserted only
when all pending transactions, interrupts,
or DMA requests are processed. This is
0x3
Smart-idle wakeup-capable mode
the best approach to efficient system
power management. The module may
generate (IRQ- or DMA-request-related)
wake-up events when in IDLE state. The
mode is relevant only if the appropriate
module swakeup output(s) is
implemented.
The idle status of a slave module is indicated by the CM_<Powerdomain>_<Module>_CLKCTRL[x]
IDLEST bit field in the PRCM module.
Table 8-4. Idle States for a Slave Module
IDLEST Bit VALUE
Idle Status
Description
The module is fully functional.The
0x0
Functional
interface and functional clocks are active.
The module is performing a wake-up or a
0x1
In transition
sleep transition.
The module interface clock is idled. The
0x2
Interface idle
module may remain functional if using a
separate functional clock.
The module is fully idle. The interface and
0x3
Full idle
functional clocks are gated in the module.
For the idle protocol management on the PRCM module side, the behavior of the PRCM module is
configured in the CM_<Power domain>_<module>_CLKCTRL[x] MODULEMODE bit field. Based on the
configured behavior, the PRCM module asserts the idle request to the module unconditionally (that is,
immediately when the software requests).
Table 8-5. Slave Module Mode Settings in PRCM
MODULEMODE Bit VALUE
Selected Mode
Description
The PRCM module unconditionally asserts
the module idle request. This request
applies to the gating of the functional and
interface clocks to the module. If
0x0
Disabled
acknowledged by the module, the PRCM
module can gate all clocks to the module
(that is, the module is completely
disabled)..
0x1
Reserved
NA
503
SPRUH73H – October 2011 – Revised April 2013
Power, Reset, and Clock Management (PRCM)
Copyright © 2011–2013, Texas Instruments Incorporated