Product data

HD404818 Series
26
Operating Modes
The MCU has five operating modes that are specified by how the clock is used. The functions available in
each mode are listed in table 15, and operations are shown in table 16. Transitions between operating
modes are shown in figure 9.
Table 16 provides additional information for table 26.
Table 15 Functions Available in Each Operating Mode
Mode Name
Active Standby Stop Watch Subactive*
4
Activation method RESET
cancellation,
interrupt
request
SBY
instruction
TMA3 = 0,
STOP
instruction
TMA3 = 1,
STOP
instruction
INT
0
or timer A
interrupt
request from
watch mode
Status System oscillator OP OP Stopped Stopped Stopped
Subsystem oscillator OP OP OP *
1
OP OP
Instruction execution
(ø
CPU
)
OP Stopped Stopped Stopped OP
Peripheral function,
interrupt (ø
PER
)
OP OP Stopped Stopped OP
Clock function,
interrupt (ø
CLK
)
OP OP Stopped OP *
2
OP *
2
RAM OP Retained Retained Retained OP
Registers/flags OP Retained Reset Retained OP
I/O OP Retained High
impedance*
3
Retained*
3
OP *
3
Cancellation method RESET input,
STOP/SBY
instruction
RESET input,
interrupt
request
RESET input RESET input,
INT
0
or timer A
interrupt
request
RESET input,
STOP/SBY
instruction
Notes: OP indicates operating.
1. To reduce current dissipation, stop all oscillation in external circuits.
2. Refer to the Interrupt Frame section for details.
3. Refer to interrupt frame.
4. Subactive mode is an optional function to be specified on the function option list.
5. In the watch and subactive modes, the MCU requires a 32.768-kHz crystal oscillator.