User Manual
124
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
System Control Unit - Digital Modules (SCU-DM)
7.4
Reset Control
This section describes the types of reset and the effects of each reset on the TLE984xQX.
7.4.1
Types of Reset
The following reset types are recognized by the TLE984xQX.
• Power-on reset
– Requested asynchronously and released by supply voltage
V
S
reaching the upper threshold. Indication
is a direct analysis of
V
S
undervoltage.
• Brown-out reset
– Is not differentiated by system with power-on reset.
• Wake-up reset
– Requested asynchronously by wake-up event during power save mode.
• Hardware reset
– Requested asynchronously by event on external reset input (pin) .
• WDT1 reset
– Activated asynchronously by external WDT1 reset event .
• Soft reset
– Requested synchronously by soft reset event.
7.4.2
Overview
When the TLE984xQX is first powered up or with brown-out condition triggered by supply voltage input(s)
going below the threshold, proper voltage thresholds must be reached before the MCU system starts
operation with the release of the MCU, CPU and NVM resets. With all resets (except soft and SCU watchdog
timer resets), the boot configuration is latched. The CPU starts to execute from the Boot ROM firmware with
the release of MCU reset.
If the system is in power save mode, it is possible to wake-up with reset. Wake-up reset is basically equivalent
to power-on reset except that it is a ‘warm’ reset and certain settings or configuration of the system are
maintained across the reset . A wake-up via hard reset pin while in power save mode is effected as wake-up
reset.
The hardware reset function via pin can be used anytime to restart the system.
The external watchdog timer (WDT1) can trigger a WDT1 reset on the system, if the timer is not refreshed
before it overflows.
Soft reset can be triggered by application software where applicable.
Note that the boot configuration is only latched with the power-on, brown-out, WDT1, wake-up and hardware
resets.
7.4.3
Module Reset Behavior
gives an overview on how the various modules or functions of the TLE984xQX are affected with
respect to the reset type. A “n” means that the module/function is reset to its default state. Refer to
for effective reset as priority.