Pulse Stretcher

The timer can be configured to produce a minimum pulse width when the ERS input rises as per the settings shown in Table 2-9.

Table 1. Timer Configuration
Timer Setting	Value
START	Rising ERS Edge
RESET	At PR Match
STOP	At PR Match
CSYNC (Clock Sync)	Sync
EPOL (ERS Polarity)	True Level (to trigger to rising edge) Inverted Level (to trigger to falling edge)
PR (Period Register)	Desired minimum pulse width

Initialize the timer counter by setting the CLR command. When the input rises (changes from 0 to 1), the counter will begin counting. Any more input changes will be ignored unless a rising edge occurs near the PR match, which will override the Stop condition, reset the counter, and continue counting. This is shown in Figure 2-12.

If OM = 1 (level), the output will be a pulse of duration (timer clock period) * (PR+1), beginning immediately upon the input edge, and continuing as long as ERS toggles. If OM = 0 (pulse), a pulse will appear some time after the original rising edge when the PR match occurs, and possibly repeat periodically.

Triggering from falling edges or either edge is accomplished by setting EPOL = 1 or START = Either ERS Edge.

Figure 1. Pulse Stretcher