Public Version
MPU Subsystem Functional Description
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Table 4-14. MPU Subsystem Operation Power Modes (continued)
Mode
MPU and
ARM L2 RAM
NEON
MPU INTC
APB/ATB Debug Comments
ARM Core
and ETM
Logic
5
Active
OFF
Active
Active
Disabled or
Active mode, L2 is off. Controlled
enabled
via SW to PRCM. L2 context save
and restore required or L2 flush.
6
Active
OFF
OFF
Active
Disabled or
Active mode, L2 is off. Controlled
enabled
via SW to PRCM. L2 context save
and restore required or L2 flush.
7
OFF
RET
OFF
OFF
Disabled or
Lowest power sleep mode (dormant
enabled
mode), L2 is in retention. Controlled
via SW to PRCM. ARM core and L1
context save and restore required or
L1 flush.
8
Standby
Active
Standby
Active
Disabled or
Standby mode. StandbyWFI
enabled
controlled to put into standby and
wakeup via interrupt.
9
Standby
Active
OFF
Active
Disabled or
Standby mode. StandbyWFI
enabled
controlled to put into standby and
wakeup via interrupt when NEON is
off.
10
Standby
RET
Standby
Active
Disabled or
Standby mode (retention mode).
enabled
StandbyWFI controlled to put into
standby and wakeup via interrupt
when L2 is in retention.
11
Standby
RET
OFF
Active
Disabled or
Standby mode (retention mode).
enabled
StandbyWFI controlled to put into
standby and wakeup via interrupt
when L2 is in retention and NEON
is off.
12
Standby
OFF
Standby
Active
Disabled or
Standby mode. StandbyWFI
enabled
controlled to put into standby and
wakeup via interrupt when L2 is off.
13
Standby
OFF
OFF
Active
Disabled or
Standby mode. StandbyWFI
enabled
controlled to put into standby and
wakeup via interrupt when both L2
and NEON are off.
14
OFF
OFF
OFF
OFF
Disabled or
Power-down mode
enabled
In any mode where the MPU or NEON power domains are active, the MPU DPLL clocks must be active
(modes 1, 3, and 5 require active clocks from the DPLL, while Modes 7 and 8 do not).
Thus, the MPU DPLL must be in one of these states:
•
Locked state
•
Low power bypass state: inclk = on, clkout = on, power = on
When the MPU DPLL is not providing clocks, the MPU subsystem must be in a power mode where the
MPU power domain, NEON power domain, debug power domain, and INTC power domain are in standby,
retention, or off state. The states of the MPU DPLL can be:
•
Locked
•
STOP low power
•
OFF
4.3.2.4
Transitions
describes allowable transitions from power modes described in
. For example, a
transition from mode 13 to mode 4 is allowed, but the reverse is not true because the L2 RET to OFF is
illegal.
688
MPU Subsystem
SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated