Features
191
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Power Management
9.4
Features
This device has several means of managing power consumption, as detailed in the subsequent sections.
This device uses the state-of-the-art 65 nm process, which provides a good balance on power and
performance, providing high-performance transistors with relatively less leakage current and, thereby, low
standby-power consumption modes.
There are several features in design as well as user driven software control to reduce dynamic power
consumption. The design features (not under user control) include a power optimized clock tree design to
reduce overall clock tree power consumption and automatic clock gating in several modules when the
logic in the modules is not active.
The on-chip power and sleep controller (PSC) module provides granular software controlled module level
clock gating, which reduces both clock tree and module power by basically disabling the clocks when the
modules are not being used. Clock management also allows you to slow down the clocks, to reduce the
dynamic power.
describes the power management features.
Table 9-1. Power Management Features
Power Management
Description
Features
Clock Management
PLL bypass and power-
down
Both PLLs can be powered-down and run in
bypass mode when not in use.
Reduces the dynamic power consumption of the
core.
Module clock ON
Module clocks can be turned on/off without
requiring reconfiguring the registers.
Reduces the dynamic power consumption of the
core and I/O (if any free running I/O clocks).
Core Sleep Management
ARM subsystem
sleep modes
The ARM CPU can be put in sleep mode.
Additionally, the ARM subsystem clock can be
completely gated when not in use.
Reduces the dynamic power consumption.
Voltage Management
RTC-only mode
Allows removing power from all core and I/O
supply and just have the real-time clock (RTC)
running.
Reduces the dynamic and static power for standby
modes that require only the RTC to be functional.
Dynamic Voltage and Frequency Scaling
Dynamic Voltage and
Frequency Scaling
(DVFS)
The operating voltage and frequency of the device
can be dynamically scaled to meet the
requirements of the application.
Reduces the dynamic power consumption of the
core and I/O as well as standby power
System/Device Sleep Management
Deep Sleep Mode
All internal clocks of the device can be turned
on/off at the OSCIN level. The deep sleep function
can be controlled externally through the
DEESLEEP pin or internally through the
RTC_ALARM pin.
Reduces the dynamic power consumption of the
core and I/O.
Peripheral I/O Power Management
USB PHY power-down
The USB2.0 PHY can be powered-down.
Minimizes the USB2.0 I/O power consumption
when not in use.
DDR2/mDDR self-
refresh mode
Allows memory to retain its contents while the rest
of the system is powered down.
mDDR and DDR2 can be clock gated to reduce the
dynamic power consumption or the entire device
can be powered down to reduce the static power
consumption.
SATA PHY power-down
The SATA PHY can be placed in standby mode.
Minimizes the SATA I/O power consumption when
not in use.
LVCMOS I/O buffer
receiver disable
LVCMOS I/O buffer receivers are disabled.
Minimizes the I/O power consumption.
Internal pull-up and pull-
down resistor control
The internal pull-ups and pull-downs are
enabled/disabled by groups.
Reduces the I/O leakage power.