5 power configurations – Texas Instruments TMS3320C5515 User Manual

Page 50

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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

Table 1-31

. 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

50

System Control

SPRUFX5A – October 2010 – Revised November 2010

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