ST STM8S

AN2752 Rev 6 15/40
AN2752 Reset control
39
Output characteristics
• A valid pulse on the pin is guaranteed with a pulse whose duration is higher than 20 ns
on the internal output buffer.
• After a valid pulse is recognized, a pulse of at least 20 µs is guaranteed on the pin,
starting from the falling edge of A.
Figure 8. Output characteristics
Input characteristics
• All pulses with a duration lower than 75 ns are filtered
• All train/burst spikes with a ratio of 1/10 must be filtered. This means that a negative
spike of up to 75 ns is always filtered, when a 7.5 ns interval between spikes occurs
(ratio 1/10).
• All pulses with duration longer than 450 ns are recognized as valid
• After a valid pulse is recognized, an internal pulse of at least 30 ns is guaranteed
Figure 9. Input characteristics
≥ 20 ns
20 µs pulse stretch min
A
Pad
Reset requested
Pad
System reset
>7.5 ns >7.5 ns
<75 ns <75 ns <75 ns
450 ns
>30 ns
Reset requestedNegative train of glitch filtered