Section 11 Watchdog Timer (WDT)
Rev. 3.00 Sep. 27, 2007 Page 405 of 758
REJ09B0243-0300
11.3.2
Watchdog Timer Control/Status Register (WTCSR)
WTCSR is an 8-bit readable/writable register composed of bits to select the clock used for the
count, bits to select the timer mode, and overflow flags. WTCSR holds its value in an internal
reset due to the WDT overflow. WTCSR is initialized to H'00 only by a power-on reset using the
RES
pin.
When used to count the clock settling time for canceling a software standby, it retains its value
after counter overflow. Use a word access to write to WTCSR, with H'A5 in the upper byte. Use a
byte access to read WTCSR.
Note: WTCSR differs from other registers in that it is more difficult to write to. See section
11.3.3, Notes on Register Access, for details.
Bit:
Initial value:
R/W:
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
TME
WT/IT
RSTS
WOVF
IOVF
CKS[2:0]
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 to revoke software standby mode
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: Interval timer mode
1: Watchdog timer mode
Note: If WT/IT is modified when the WDT is operating,
the up-count may not be performed correctly.
Summary of Contents for SH7124 R5F7124
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Page 36: ...Section 1 Overview Rev 3 00 Sep 27 2007 Page 16 of 758 REJ09B0243 0300 ...
Page 68: ...Section 2 CPU Rev 3 00 Sep 27 2007 Page 48 of 758 REJ09B0243 0300 ...
Page 108: ...Section 5 Exception Handling Rev 3 00 Sep 27 2007 Page 88 of 758 REJ09B0243 0300 ...
Page 166: ...Section 7 User Break Controller UBC Rev 3 00 Sep 27 2007 Page 146 of 758 REJ09B0243 0300 ...
Page 724: ...Section 20 List of Registers Rev 3 00 Sep 27 2007 Page 704 of 758 REJ09B0243 0300 ...
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