CHAPTER 8 WATCHDOG TIMER
User's Manual U11919EJ3V0UM00
117
8.3 Watchdog Timer Control Registers
The following two types of registers are used to control the watchdog timer.
• Timer clock select register 2 (TCL2)
• Watchdog timer mode register (WDTM)
(1)
Timer clock select register 2 (TCL2)
This register sets the watchdog timer count clock.
TCL2 is set with an 8-bit memory manipulation instruction.
RESET input clears TCL2 to 00H.
Figure 8-2. Timer Clock Select Register 2 Format
TCL22
0
0
1
1
0
0
0
0
0
TCL22
TCL21
TCL20
TCL2
R/W
R/W
7
6
5
4
3
2
1
0
TCL21
0
1
0
1
f
X
/2
4
f
X
/2
6
f
X
/2
8
f
X
/2
10
(312.5 kHz)
(78.1 kHz)
(19.5 kHz)
(4.88 kHz)
TCL20
0
0
0
0
Setting prohibited
Symbol
Address
FF42H
00H
After Reset
Other than above
Watchdog Timer Count Clock Selection
2
11
/f
X
2
13
/f
X
2
15
/f
X
2
17
/f
X
(410 s)
(1.64 ms)
(6.55 ms)
(26.2 ms)
Interval Time
µ
Remarks 1. f
X
: System clock oscillation frequency
2. The parenthesized values apply to operation at f
X
= 5.0 MHz.
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