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There are three interrupts that the real time clock can generate and these are TICK (200 times a second - 5ms), SEC (once a second) and MIN (once a minute). TSTA may be set for all three events at once, or individually (all at once means that a TICK made a new second and that second made a minute).
STA.TIME is also set when TSTA.MIN/SEC/TICK are set.
Three registers are associated with these interrupts:
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