upd78f0124m6gba1-8et Renesas Electronics Corporation., upd78f0124m6gba1-8et Datasheet - Page 229

• Manufacturer Part Number: upd78f0124m6gba1-8et
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

(4) When CPU clock and watchdog timer operation clock are the internal oscillation clocks (f
10.4.4 Watchdog timer operation in HALT mode (when “Internal oscillator can be stopped by software” is
X1 input clock (f
watchdog timer is the X1 input clock (f
started again using the operation clock before the operation was stopped. At this time, the counter is not cleared to 0
but holds its value.
The watchdog timer stops counting during HALT instruction execution regardless of whether the CPU clock is the
Figure 10-7. Operation in STOP Mode (CPU Clock and WDT Operation Clock: Internal Oscillation Clock)
CPU operation
STOP instruction is executed
When the STOP instruction is executed, operation of the watchdog timer is stopped. After STOP mode is
released, counting is started again using the operation clock before the operation was stopped. At this time, the
counter is not cleared to 0 but holds its value.
CPU operation
Watchdog timer
Watchdog timer
selected by mask option)
XP
f
f
f
XP
XP
XT
f
f
R
R
Normal operation
Normal operation
), internal oscillation clock (f
oscillation clock)
(internal
Operating
Operating Operation stopped
Operation stopped
Oscillation
stopped
Figure 10-8. Operation in HALT Mode
STOP
XP
HALT
) or internal oscillation clock (f
CHAPTER 10 WATCHDOG TIMER
User’s Manual U16315EJ3V1UD
R
), or subsystem clock (f
Clock supply stopped
Oscillation stabilization time
(set by OSTS register)
17 clocks
Operating
R
). After HALT mode is released, counting is
Normal operation (internal oscillation clock)
Normal operation
XT
), or whether the operation clock of the
Operating
R
) when the
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