miriac SBC-S32V234 User Manual
V 1.0
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© MicroSys Electronics GmbH 2018
3.8.2 Power-Up
During a power-up sequence, the MCU first checks the input voltage to be within
their necessary limits. After that, the POL
(Point Of Load)
regulators on the module
will be activated. Any regulators on the carrier board should track the correspond-
ing voltages on pins B15 and B16 of the module connector. If all module voltages
are o.k. the reset sequence will be started. If there is no external reset request, e.g.
via RSTIN# from the reset key, the RESET# will be released after 100ms. A low
level on the RSTIN# line extends this time. During normal operation, a falling edge
at RSTIN# initiates a reset sequence for the whole system, which is at least 100ms
long. As long the reset line is low, the system will be held in the reset state. If the
signal is released, the CPU will fetch its power-up configuration and starts up with
its BIST
and/or boot sequence. The RSTOUT# signal will directly follow the
state of
the RESET# signal. As long the RSTOUT# is active all connected devices must be
held in a reset state in order not to block the power-up configuration settings.
+12V
PWEN
V(intern)
RSTIN#
RSTOUT#
PORST#
If the MCU detects any overvoltage, it will turn off all internal point of load regula-
tors.
