FUJITSU F2MCTM-16LX - Manual (Page 290)

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CHAPTER 15 WATCH TIMER
Table 15.3-1 Functions of Watch Timer Control Register (WTC)
Bit Name Function
bit7 WDCS:
Watchdog clock select bit This bit selects the operation clock of the watchdog timer.
The watch timer and the timebase timer operate asynchronously. When the WDCS bit is
changed from 0 to 1, the watchdog timer may run fast. The watchdog timer must be
cleared before and after changing the WDCS bit.
bit6 SCE:
Oscillation stabilization wait
time end bit This bit indicates that the oscillation stabilization wait time of the subclock ends.
When cleared to "0": Subclock in oscillation stabilization wait state
When set to "1" : Subclock oscillation stabilization wait time ends
• The oscillation stabilization wait time of the subclock is fixed at 2
14
/SCLK (SCLK:
subclock frequency).
bit5 WTIE:
Overflow interrupt enable bit This bit enables or disables generation of an interrupt request when the watch timer counter
overflows (carries).
When set to "0": Interrupt request not generated even at overflow (WTOF=1)
When set to "1": Interrupt request generated at overflow (WTOF = 1)
bit4 WTOF:
Overflow flag bit This bit is set to "1" when the counter value of the watch timer reaches the value set by the
interval time select bit.
When an overflow carry occurs (WTOF = 1) with interrupt request enabled (WTIE = 1), an
interrupt request is generated.
When set to "0": Clears watch timer counter
When set to "1": No effect
•
The overflow flag bit is set to "1" when the bit of the watch timer counter corresponding
to the interval time set by the interval time select bits (WTC2 to WTC0) overflows (car-
ries).
bit3 WTR:
Watch timer clear bit This bit clears the watch timer counter.
When set to "0": Clears watch timer counter to "0000
H
".
When set to "1": No effect
Read: 1 is always read.
bit2
to
bit0
WTC2, WTC1, WTC0:
Interval time select bits These bits set the interval time of the watch timer.
•
When the interval time set by the WTC2 to WTC0 bits is reached, the corresponding bit
of the watch timer counter overflows (carries) and the overflow flag bit is set
(WTC:WTOF = 1).
• To set the WTC2 to WTC0 bits, set the WTOF bit to 0.