upd78f0103hmca1-5a4-a Renesas Electronics Corporation., upd78f0103hmca1-5a4-a Datasheet - Page 173

• Manufacturer Part Number: upd78f0103hmca1-5a4-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

9.2 Configuration of Watchdog Timer
9.3 Registers Controlling Watchdog Timer
(1) Watchdog timer mode register (WDTM)
Watchdog timer enable
register (WDTE)
The watchdog timer includes the following hardware.
The watchdog timer is controlled by the following two registers.
• Watchdog timer mode register (WDTM)
• Watchdog timer enable register (WDTE)
This register sets the overflow time and operation clock of the watchdog timer.
This register can be set by an 8-bit memory manipulation instruction and can be read many times, but can be
written only once after reset is released.
RESET input sets this register to 67H.
f
XP
f
R
/2
/2
4
2
Control registers
controller
Clock
input
2
Item
Watchdog timer mode
register (WDTM)
0
Figure 9-1. Block Diagram of Watchdog Timer
counter
Table 9-3. Configuration of Watchdog Timer
16-bit
1
Clear
CHAPTER 9 WATCHDOG TIMER
Watchdog timer mode register (WDTM)
Watchdog timer enable register (WDTE)
1
2
2
or
2
2
Internal bus
11
18
13
20
User’s Manual U16846EJ3V0UD
/f
/f
/f
/f
XP
XP
R
R
WDCS4
to
to
Selector
WDCS3
3
WDCS2
Configuration
WDCS1 WDCS0
controller
Output
Internal reset signal
Option byte
(to set
cannot be
“Internal oscillator
stopped by software”)
“Internal oscillator
stopped”
can be
or
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