MB3773
Description of Application Circuits
Using one MB3773, this application circuit monitors multiple microcomputers in one system. Signals from each microcomputer
are sent to FF1, FF2 and FF3 clock inputs. Figure 2 shows these timings. Each flip-flop operates using signals sent from mi-
crocomputers as its clock pulse. When even one signal stops, the relevant receiving flip-flop stops operating. As a result, cy-
clical pulses are not generated at output Q3. Since the clock pulse stops arriving at the CK pin of the MB3773, the MB3773
generates a reset signal.
Note that output Q3 frequncy f will be in the following range, where the clock frequencies of CK1, CK2 and CK3 are f1, f2 and f3
respectively.
1
f0
1
f
1
1
1
f
3
--- --
≤
≤ ---- --- ----
+ +
f
1
f
2
where f0 is the lowest frequency among f1, f2 and f3.
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