ST10F272B_12 STMICROELECTRONICS [STMicroelectronics], ST10F272B_12 Datasheet - Page 92

• Manufacturer Part Number: ST10F272B_12
• Description: 16-bit MCU with 256 Kbyte Flash memory and 12/20 Kbyte RAM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

System reset
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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 (around 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
the input threshold: the asynchronous reset is completed coherently. To grant the normal
completion of a synchronous reset, the value of the capacitance shall be big enough to
maintain the voltage on RPD pin sufficient high along 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).
Doc ID 11917 Rev 3
Figure
18. There is no effect if RPD comes again above
ST10F272B/ST10F272E