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Section 5 Watchdog Timer (WDT)
Rev. 4.00 Sep. 14, 2005 Page 157 of 982
REJ09B0023-0400
5.2.2
Watchdog Timer Control/Status Register (WTCSR)
The watchdog timer control/status register (WTCSR) is an 8-bit readable/writable register
composed of bits to select the clock used for the count, overflow flags, and timer enable bit. The
WTCSR register holds its value in an internal reset due to WDT overflow. The WTCSR register is
initialized to H'00 only by a power-on reset caused by the
RESETP
pin.
When used to count the clock settling time for canceling a standby, it retains its value after counter
overflow. Use a word access to write to the WTCSR counter, writing H'A5 in the upper byte. Use
a byte access to read the WTCSR.
Note: The WTCNT differs from other registers in the prevention of erroneous writes.
See section 5.2.3, Notes on Register Access, for details.
Bit Bit
Name
Initial
Value R/W Description
7 TME 0 R/W
Timer
Enable
Starts and stops timer operation. Clear this bit to 0
when using the WDT in standby mode or when
changing the clock frequency.
0: Timer disabled: Count-up stops and WTCNT value
is retained
1: Timer enabled
6 WT/
IT
0
R/W
Timer Mode Select
Selects whether to use the WDT as a watchdog timer
or an interval timer.
0: Use as interval timer
1: Use as watchdog timer
Note: If
WT/
IT
is modified when the WDT is running,
the up-count may not be performed correctly.
5 RSTS
0 R/W
Reset
Select
Selects the type of reset when the WTCNT overflows
in watchdog timer mode. In interval timer mode, this
setting is ignored.
0: Power-on reset
1: Manual reset
Содержание HD6417641
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Страница 204: ...Section 4 Clock Pulse Generator CPG Rev 4 00 Sep 14 2005 Page 154 of 982 REJ09B0023 0400...
Страница 212: ...Section 5 Watchdog Timer WDT Rev 4 00 Sep 14 2005 Page 162 of 982 REJ09B0023 0400...
Страница 228: ...Section 6 Power Down Modes Rev 4 00 Sep 14 2005 Page 178 of 982 REJ09B0023 0400...
Страница 246: ...Section 8 X Y Memory Rev 4 00 Sep 14 2005 Page 196 of 982 REJ09B0023 0400...
Страница 318: ...Section 11 User Break Controller UBC Rev 4 00 Sep 14 2005 Page 268 of 982 REJ09B0023 0400...
Страница 454: ...Section 12 Bus State Controller BSC Rev 4 00 Sep 14 2005 Page 404 of 982 REJ09B0023 0400...
Страница 500: ...Section 13 Direct Memory Access Controller DMAC Rev 4 00 Sep 14 2005 Page 450 of 982 REJ09B0023 0400...
Страница 504: ...Section 14 U Memory Rev 4 00 Sep 14 2005 Page 454 of 982 REJ09B0023 0400...
Страница 566: ...Section 17 Compare Match Timer CMT Rev 4 00 Sep 14 2005 Page 516 of 982 REJ09B0023 0400...
Страница 734: ...Section 18 Multi Function Timer Pulse Unit MTU Rev 4 00 Sep 14 2005 Page 684 of 982 REJ09B0023 0400...
Страница 868: ...Section 21 A D Converter Rev 4 00 Sep 14 2005 Page 818 of 982 REJ09B0023 0400...
Страница 914: ...Section 23 I O Ports Rev 4 00 Sep 14 2005 Page 864 of 982 REJ09B0023 0400...
Страница 956: ...Section 24 List of Registers Rev 4 00 Sep 14 2005 Page 906 of 982 REJ09B0023 0400...
Страница 1016: ...Section 25 Electrical Characteristics Rev 4 00 Sep 14 2005 Page 966 of 982 REJ09B0023 0400...
Страница 1024: ...Appendix Rev 4 00 Sep 14 2005 Page 974 of 982 REJ09B0023 0400...
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