5 power configurations – Texas Instruments TMS3320C5515 User Manual
Page 50
Power Management
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1.5.5 Power Configurations
The power-saving features described in the previous sections, such as peripheral clock gating, and
on-chip memory power down to name a few, can be combined to form a power configuration. Many
different power configurations can be created by enabling and disabling different power domains and clock
domains, however, this section defines some basic power configurations that may be useful. These are
shown and described in
. Please note that there is no single instruction or register that can
place the device in these power configurations. Instead, these power configurations are achieved by
modifying multiple registers.
NOTE:
Before you change the power configuration, make sure that there is a method for the device
to exit the power configuration. After exiting a power configuration, your software may have
to take additional steps to change the clock and power configuration for other domains.
NOTE:
The on-chip Bootloader idles all peripherals and CPU ports at startup. It enables some
peripherals as it uses them. Your application code should check the idle configuration of
peripherals and CPU ports before using them to be sure these are not idle.
Table 1-31. Power Configurations
Steps to Enter Clock
Available Methods for
Power
Power Domain
and Power
Changing/Exiting Clock and
Configuration
State
Clock Domain State
Configuration
Power Configuration
RTC only mode
DV
DDRTC
, LDOI,
Only RTC clock is
Set LDO_PD and
A. RTC interrupt
and CV
DDRTC
running
BG_PD bits in
B. WAKEUP pin
powered all others
RTCPMGT register
powered-down
IDLE3
All power domains
RTC clock domain
Idle peripheral domain
A. WAKEUP pin
on
enabled
Other clock domains
Idle CPU domain
B. RTC interrupt
disabled. Clock
generator domain
disabled (BYPASS
MODE and PLL
powerdown).
PLL in BYPASS MODE C. External hardware interrupt (INT0
PLL powerdown
or INT1).
Master clock disable
D. Hardware Reset
Execute idle instruction
IDLE2
All power domains
RTC clock domain
Idle peripheral domains A. WAKEUP pin
on
enabled
Clock generator domain
Idle CPU domain
B. RTC interrupt
enabled (PLL_MODE)
Other clock domains
Execute idle instruction
C. External hardware interrupt
disabled
(INT0, INT1).
D. Any unmasked peripheral
interrupt.
E. Hardware Reset
Active
All power domains
All clock domains
Turn on all power
on
enabled
domains
Enable all clock
domains
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System Control
SPRUFX5A – October 2010 – Revised November 2010
Copyright © 2010, Texas Instruments Incorporated