HD404369 Datasheet, PDF (28/117 Pages) Hitachi Semiconductor – 4-bit HMCS400-Series microcomputer

HD404369 Series
Operating Modes
The MCU has five operating modes as shown in table 17. The operations in each mode are listed in tables
18 and 19. Transitions between operating modes are shown in figure 11.
Active Mode: All MCU functions operate according to the clock generated by the system oscillator OSC ₁
and OSC₂.
Table 17 Operating Modes and Clock Status
Mode Name
Active
Standby Stop
Watch
Subactive*²
Activation method
RESET cancellation,
interrupt STOPC
cancellation in stop
mode, STOP/SBY
instruction in
subactive mode
(when direct transfer
is selected)
SBY
instruction
STOP
STOP
INT₀ or timer A
instruction when instruction when interrupt request
TMA3 = 0
TMA3 = 1
from watch
mode
Status System OP
oscillator
OP
Stopped
Stopped
Stopped
Subsystem OP
oscillator
OP
*¹ OP
OP
OP
Cancellation
method
RESET input,
RESET
STOP/SBY instruction input,
interrupt
request
RESET input, RESET input, RESET input,
STOPC input in INT₀ or timer A STOP/SBY
stop mode
interrupt request instruction
Notes: OP implies in operation
1. Operating or stopping the oscillator can be selected by setting bit 3 of the system clock select
register 1 (SSR1: $027).
2. Subactive mode is an optional function; specify it on the function option list.
26