HD404669 Datasheet, PDF (31/142 Pages) Hitachi Semiconductor – Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit

HD404669 Series
Operating Modes
The MCU has five operating modes as shown in table 11. The operations in each mode are listed in table
12. Transitions between operating modes are shown in figure 14.
Table 11
Operating Modes and Clock Status
Activation
method
Status
System
oscillator
Active
RESET
cancellation,
interrupt
request,
STOPC
cancellation
in stop mode,
STOP/SBY
instruction in
subactive mode
(when direct
transfer is
selected)
Operation
Standby
SBY
instruction
Operation
Mode Name
Stop
STOP
instruction
when
TMA3 = 0
Watch
Subactive*²
STOP
instruction
when
TMA3 = 1
STOP/SBY
instruction in
subactive mode
(except when
direct transition is
specified)
INT₀ or timer A
interrupt request
from watch
mode
when
LSON = 1
Stopped
Stopped
Stopped
Subsystem
oscillator
Operation
Operation
*¹
Operation
Operation
Cancellation
method
RESET input,
STOP/SBY
instruction
RESET input, RESET input,
interrupt
STOPC input
request
RESET input,
INT₀ or timer A
interrupt
request
RESET input,
STOP/SBY
instruction
Notes: 1. Operating or stopping the oscillator can be selected by setting bit 3 of the system clock select
register (SSR: $029).
2. Subactive mode is an optional function; specify it on the function option list.
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