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Chapter 23 Sub Oscillation Stabilisation Timer
5.Operation
5.2 Interval Interrupt (Clock Interrupt)
(1) Selects the interval time. (WS[1:0]) (In this example, 213/FCL-SUBis selected.)
(2) Sets the timer clear (WCL=“0”), flag clear (WIF=“0”) and interrupt request enable (WIE=“1”) by the software.
(3) The timer counts up with the subclock (Source oscillation).
(4) Makes the interval time be the selected time. (Detects the fall of 213.)
(5) If the flag (WIF) is set to “1”, interval interrupt request (Clock interrupt request) is generated.
(6) Processing caused by an interrupt (Software): The interrupt request clear (WIF=“0”)
(Arbitrary processing such as clock counting)
(7) Repeats Items (3) to (6).
WIF
Clock timer
counting
Time
2000h
0000h
(2)
(2)
(4)
(2)
WCL
(1)
WIE
(2)
(5) (6) (6)
(4)
(5)
(3)
4000h
213 (Bit12)
(4)
(4)
(3)