HD404849 Datasheet, PDF (28/125 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

HD404849 Series
Operating Modes
The MCU has five operating modes as shown in table 19. The operations in each mode are listed in tables
20 and 21. Transitions between operating modes are shown in figure 14.
Table 19 Operating Modes and Clock Status
Mode Name
Active
Standby
Stop
Watch
Subactive*²
Activation
method
Reset
SBY
cancellation, instruction
interrupt
request
STOPC
cancellation in
stop mode,
STOP/SBY
instruction in
subactive
mode (when
direct transfer
is selected)
STOP
instruction
when
TMA3 = 0
STOP
instruction
when
TMA3 = 1
INT₀ or timer A
interrupt
request from
watch mode
Status
System OP
OP
Stopped
Stopped
Stopped
oscillator
Subsystem OP
OP
OP *¹
OP
OP
oscillator
Cancellation
method
RESET input,
STOP/SBY
instruction
RESET input,
interrupt
request
RESET input,
STOPC input
in stop mode
RESET input RESET input,
INT₀ or timer A STOP/SBY
interrupt
instruction
request
Notes: OP implies in operation.
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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