ST10F272M-4Q3 STMICROELECTRONICS [STMicroelectronics], ST10F272M-4Q3 Datasheet - Page 85

• Manufacturer Part Number: ST10F272M-4Q3
• Description: 16-bit MCU with 256 Kbyte Flash memory and 20 Kbyte RAM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

ST10F272M
System reset
behavior when booting from internal or external memory respectively. Figures
23
and
24
report the timing of a typical synchronous Long Reset, again when booting from internal or
external memory.
Synchronous reset and RPD pin
Whenever the RSTIN pin is pulled low (by external hardware or as a consequence of a
Bidirectional reset), the RPD internal weak pull-down is activated. The external capacitance
(if any) on RPD pin is slowly discharged through the internal weak pull-down. If the voltage
level on RPD pin reaches the input low threshold (approximately 2.5V), the reset event
becomes immediately asynchronous. In case of hardware reset (short or long) the situation
goes immediately to the one illustrated in
Figure
19. There is no effect if RPD comes again
above the input threshold: the asynchronous reset is completed coherently. To correctly
complete a synchronous reset, the value of the capacitance must be big enough to maintain
a sufficiently high voltage on the RPD pin for the duration of the internal reset sequence.
For a Software or Watchdog reset events, an active synchronous reset is completed
regardless of the RPD status.
It is important to highlight that the signal that makes RPD status transparent under reset is
the internal RSTF (after the noise filter).
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