FUJITSU MB91460 SERIES FR60 - Manual (Page 293)

277
Chapter 20 Software Watchdog Timer
4.Register
4.2 WPR: Watchdog Reset Generation Postponement Register
This register is used to postpone the generation of watchdog reset.
• WPR: Address 0485h (Access: Byte)
(Refer to “ Meaning of Bit Attribute Symbols (Page No.10) ” for the attributes.)
• If “A5
H
” and “5A
H
” are successively written in the watchdog reset generation postponement register and
immediately after writing “5A
H
” the 1-bit counter used to detect the watchdog is set to “0” to postpone the
generation of a watchdog reset.
Although there are no restrictions on the write timings for “A5
H
” and “5A
H
”, if “A5
H
” and a value other
than “5A
H
” are written, “A5
H
” must be written again. If not, writing “5A
H
” does not set the 1-bit counter to
“0”.
• The read value is indefinite.
• Both “A5
H
” and “5A
H
” must be written within the specified interval as shown below to prevent the
watchdog reset from being generated. The intervals are shown in the following table according to the
watchdog interval time selection bit (RSRR.WT[1:0]).
4.3 CTBR: Timebase Counter Clear Register
This register is used to initialize the timebase counter.
• CTBR: Address 0483h (Access: Byte)
For more information, refer to “ Chapter 19 Timebase Timer (Page No.263) ”.
7 6 5 4 3 2 1 0 bit
D7 D6 D5 D4 D3 D2 D1 D0
X X X X X X X X Initial value (INIT)
X X X X X X X X Initial value (RST)
RX,W RX,W RX,W RX,W RX,W RX,W RX,W RX,W Attribute
WT1 WT0 Minimum interval required for writing data in WPR
0 0 Within
Φ × 2 20
(Initial value)
0 1 Within
Φ × 2 22
1 0 Within
Φ × 2 24
1 1 Within
Φ Ч 2 26