User Manual
129
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
System Control Unit - Digital Modules (SCU-DM)
7.5
Power Management
This section describes the features and functionality provided for power management of the device.
7.5.1
Overview
The TLE984xQX power-management system allows software to configure the various processing units so that
they automatically adjust to draw the minimum necessary power for the application.
There are four power modes: Active Mode, Slow Down Mode, Stop Mode and Sleep Mode, as shown in
. Sleep Mode is a special case which can only be exited with a system reset.
The operation of the system components in each of these states can be configured by software. The power
modes provide flexible reduction of power consumption through a combination of techniques, including:
• Stopping the CPU clock
• Stopping the clocks of other system components individually
• Clock-speed reduction of some peripheral components
• Power-down of the entire system with fast restart capability
• Reducing or removing the power supply to power domains
Figure 32 Transition between Various Modes of Operation (without reset)
In Slow Down mode, the clock generation unit is instructed to reduce its clock frequency so that the clock to
the system, i.e. Core and peripheral, will be divided by a programmable factor.
In Stop Mode, the clock is turned off. Hence, it cannot be awakened by an interrupt or the Watchdog Timer. It
will be awakened only when it receives an external wake-up signal or reset signal. The application must be
prepared that the TLE984xQX is served with one of these signals. A wake-up circuit is used to detect enabled
wake-up signal(s) and activate the Stop Mode wake-up. During Stop Mode, this circuit remains active.
POWER-DOWN
ACTIVE
SLOW-DOWN
set PD
bit
set PD
bit
set SL
bit
set SL
bit
set SD
bit
clear SD
bit
Wake-up event
Wake-up event
& SD=0
Wake-up event
& SD=1
Transition not
possible, because
Sleep Exit is
always with reset
SLEEP
(wake up with device reset )