HD404618 Datasheet, PDF (26/91 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

HD404618 Series
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 10. Table 17 provides additional information for table 15.
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
INT₀ or timer
A interrupt
request from
watch mode
Status
System
oscillator
Operating Operating Stopped
Stopped
Stopped
Subsystem Operating
oscillator
Operating
Operating*¹ Operating
Operating
Instruction
execution
(ø_CPU)
Operating
Peripheral Operating
function
interrupt(ø_PER)
Clock function Operating
interrupt (ø_CLK)
RAM
Operating
Stopped
Operating
Operating
Retained
Stopped
Stopped
Stopped
Retained
Stopped
Operating
Stopped
Operating
Operating*² Operating*²
Retained
Operating
Registers/
flags
Operating
Retained
Reset
Retained
Operating
I/O
Operating Retained
High
Retained*³ Operating*³
impedance*³
Cancellation
method
RESET input,
STOP/SBY
instruction
RESET input,
interrupt
request
RESET input
RESET input,
INT₀ or timer
A interrupt
request
RESET input,
STOP/SBY
instruction
Notes: 1. To reduce current dissipation, stop all oscillation in external circuits.
2. Refer to the Interrupt Frame section for details.
3. Refer to table 17.
4. Subactive mode is an optional function, specify it on the function option list.
5. In the watch and subactive modes, the MCU requires a 32.768-kHz crystal oscillator.
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