Figure 8. Output Characteristics; Figure 9. Input Characteristics - ST STM8S Getting Started

AN2752
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.
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
Negative train of glitch filtered

Figure 8. Output characteristics

≥ 20 ns

Figure 9. Input characteristics

>7.5 ns >7.5 ns
<75 ns <75 ns <75 ns
AN2752 Rev 6
20 µs pulse stretch min
Reset requested
450 ns
>30 ns
Reset requested
Reset control
A
Pad
Pad
System reset
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