Renesas SH7781 - Manual (Page 796)

16. Watchdog Timer and Reset (WDT)
Rev.1.00 Jan. 10, 2008 Page 766 of 1658
REJ09B0261-0100
16.3.3 Watchdog Timer Base Stop Time Register (WDTBST)
WDTBST is a 32-bit readable/writable register that specifies the time until counter WDTBCNT
overflows when the bus clock frequency has been changed. The time until WDTBCNT overflows
becomes minimum when H'5500 0001 is set, and maximum when H'5500 0000 is set.
WDTBST should be written to as a longword unit, with H'55 in the most significant byte. The
value read from this byte is always H'00. WDTBST is only rest by a power-on reset caused by the
PRESET pin.
16 17 18 19 20 21 22 23 24 25 26 27 28 29 31 30
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
WDTBST ⎯ ⎯ ⎯ ⎯
R/W R/W R R R R R R R/W R/W R/W R/W R/W R/W R/W R/W
Bit:
Initial value:
R/W:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 15 14
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
WDTBST
R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W
Bit:
Initial value:
R/W:
Code for writing (H'55) ⎯ ⎯
Bit Bit Name
Initial
Value R/W Description
31 to 24 (Code for
writing)
All 0 R/W Code for writing (H'55)
These bits are always read as H'00. When writing to
this register, the value written to these bits must be
H'55.
23 to 18
⎯ All
0 R Reserved
These bits are always read as 0. The write value
should always be 0.
17 to 0 WDTBST All 0 R/W Base Timer Stop
These bits set the counter value at which WDTBCNT
overflows.
H'00001: Minimum overflow value
H'00000: Maximum overflow value