CHAPTER 13 STANDBY FUNCTION
User’s Manual U16898EJ3V0UD
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13.2 Standby Function Operation
13.2.1 HALT mode
(1) HALT mode
The HALT mode is set by executing the HALT instruction.
The operating statuses in the HALT mode are shown below.
Caution Because an interrupt request signal is used to clear the standby mode, if there is an interrupt
source with the interrupt request flag set and the interrupt mask flag clear, the standby mode
is immediately cleared if set.
Table 13-2. Operating Statuses in HALT Mode
Low-Speed Internal Oscillator Can Be Stopped
Note
Setting of HALT Mode
Item
Low-Speed Internal
Oscillator Cannot Be
Stopped
Note
When Low-Speed Internal
Oscillation Continues
When Low-Speed Internal
Oscillation Stops
System clock
Clock supply to CPU is stopped.
CPU Operation
stops.
Port (latch)
Holds status before HALT mode was set.
16-bit timer/event counter 00
Operable
8-bit timer 80
Operable
Sets count clock to f
XP
to f
XP
/2
12
Operable
8-bit timer
H1
Sets count clock to f
RL
/2
7
Operable
Operable
Operation
stops.
System clock selected as
operating clock
Setting prohibited
Operation stops.
Watchdog
timer
“Low-speed internal oscillation
clock” selected as operating
clock
Operable (Operation
continues.)
Operation stops.
A/D converter
Operable
Serial interface UART6
Operable
Power-on-clear circuit
Always operates.
Low-voltage detector
Operable
External interrupt
Operable
Note
“Cannot be stopped” or “Stopped by software” is selected for low-speed internal oscillator by the option byte
(for the option byte, see
CHAPTER 17 OPTION BYTE
).