User Manual
74
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
Power Management Unit (PMU)
The third hardware related reset source is the pin-reset. The pad itself is supplied by the VDDP domain which
is available in Active Mode and Stop Mode. Therefore the reset-pin can be used in Active Mode and Stop Mode
only. Due to the bidirectional use of the pin itself the pin-reset request is gated during the execution of another
reset request (e.g. soft-reset). For this purpose the pin-reset request must be stable for more than 500 ns (see
). In case of a pin-reset request during Stop Mode the PMU goes to Active Mode and sends the wake-
up signal to the MCU. At this time the reset status register also gets an update by setting bit PMU_PIN, which
signals the described reset source. All other reset sources can only have an impact on the system behavior in
Active Mode.
The reset request caused by a system watchdog, which was not serviced is also processed as a hardware
related reset although this reset request is implicitly controlled by user software. The system watchdog only
works in Active Mode. In this case it expects a periodic trigger (window watchdog) from the user software. If
the trigger is missing then the PMU gets the signal that the watchdog was not serviced which sets the
identification bit PMU_ExtWDT from WDT1. After some clock cycles of the PMU internal oscillator LP_CLK the
PMU resets the MCU. The prioritization of the described reset sources is done according to the architecture
and the functionality of the embedded system itself.
The software-reset and the reset request caused by the MCU internal watchdog are controlled explicitly by
user software and can be used only in Active Mode. From the system point of view both of these reset sources
have the lowest priority. The software related reset is executed within two MCU clock cycles which is required
by the CPU architecture. The system clock of the PMU works independently of the MCU clock. Due to these
system conditions the PMU processes the software related resets asynchronously to its internal system clock.
The software-reset is flagged by the PMU_SOFT bit. The flags is located in the above mentioned
Another reset source is the PSG module. In case the main voltage regulators (VDDP and VDDC) will fail, the
system will execute a system reset and enter Sleep Mode afterwards. This case is flagged by setting the
indication bit SYS_FAIL.
Reset types are combinations of the above described resets. The reset of an XSFR register is depending on the
corresponding reset type. Other registers (all SFRs except NMI status flags) are always reset independent of
the reset type. The figure below shows this combination of resets.
Figure 23 Reset Types of SFRS provided by the RMU
error_s
up=
5
XSFR_reset_types_customer.vsd
RESET_TYPE_0
X
So
C
pow
er-on
Sl
eep M
od
e
X
X
X
Pi
n-
Re
se
t
WD
T_
EX
T
SO
FT
error_w
dt
=5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
RESET_TYPE_1
RESET_TYPE_2
RESET_TYPE_3
RESET_TYPE_4