User Manual
132
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
System Control Unit - Digital Modules (SCU-DM)
7.5.2.2.1
Usage of Arm® Core Low Power Modes for Stop and Sleep Mode
The Arm® Core provides two low power modes, which are Sleep and Deep sleep. For stop mode of the system
the Deep sleep will be used. To enable the deep sleep mode the System Control Register at address
E000ED10
H
. When the user wants to enter sleep mode it can be done via two different instructions:
•
WFI
•
WFE
When the controller enters stop mode via WFI instruction, it executes the lowest prior pending interrupt and
after that enters sleep mode. This feature is not recommended to be used for normal operation using stop
mode, because the controller would only operate interrupt triggered.
When the WFE instruction is used, the controller starts to operate triggered by an external event. If CPU will be
woken up be this external event, it stays in thread mode and continue to execute the code before it entered
stop mode.
This is the recommended procedure to enter stop mode.
7.5.2.3
Sleep Mode
In the Sleep Mode, the supply to the whole MCU subsystem including the ADC, PLL and NVM is removed. The
wake-up detection circuitry remains supplied. Only contents of non-volatile memory are retained. As for the
external ports, only the wake-up pads are still powered. The supply to ADC pads is removed.
Sleep Mode is always exit with a system reset, which is triggered by active edge on the enabled wake-up pin(s).
It is not possible to exit Sleep Mode by asserting the hard reset pin as the digital 5 V pads will not be powered.
Software requests Sleep Mode by setting the bit PMCON0.SL to 1.
Exiting Sleep Mode
Sleep Mode can only be exited with a system reset, triggered by active edge on the enabled wake-up pin(s).
Notes
1. Ready for first LIN message at > 400 µs (assume 64 KByte MapRAM init): start-up boot, NVM pumps ramp up
including SFR and MapRAM init.
2. To avoid power switching, dedicated VREGs are provided for necessary power domains.