HD404654 Datasheet, PDF (24/109 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

HD404654 Series
Operating Modes
The MCU has three operating modes as shown in table 15. The operations in each mode are listed in tables
16 and 17. Transitions between operating modes are shown in figure 11.
Table 15 Operating Modes and Clock Status
Activation method
Status
Cancellation
method
System oscillator
Note: OP implies in operation
Mode Name
Active
Standby
RESET cancellation, SBY instruction
interrupt request,
STOPC cancellation
in stop mode
OP
OP
RESET input,
RESET input,
STOP/SBY
instruction
interrupt request
Stop
STOP instruction
Stopped
RESET input,
STOPC input in stop
mode
Table 16 Operations in Low-Power Dissipation Modes
Function
Stop Mode
CPU
Reset
RAM
Retained
Timer A
Reset
Timer C
Reset
Timer D
Reset
Serial 1
Reset
DTMF
Reset
Comparator
Reset
I/O
Reset*
Notes: OP implies in operation
* Output pins are at high impedance.
Standby Mode
Retained
Retained
OP
OP
OP
OP
OP
Stopped
Retained
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