UPD784044 Datasheet, PDF (50/90 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLER

µPD784044(A), 784046(A)
10. STANDBY FUNCTION
The µPD784046(A) has the following standby function modes that reduce the power consumption of the chip.
• HALT mode
• IDLE mode
• STOP mode
: This mode stops the operating clock of the CPU. It can reduce the average
power consumption through intermittent operation by combination of a normal
operation and this mode.
: This mode stops the entire system with the operation of the oscillation circuit
continuing. Normal program operation can be restored from this mode with
the power consumption close to that in the STOP mode and time equivalent
to that in the HALT mode.
: This mode stops the oscillator and stops all the internal operations of the chip
to minimize the power consumption to the level of only leakage current.
These modes are programmable.
Macro service can be started from the HALT mode.
Figure 10-1. Standby Status Transition
Waits for ^{Oscillatimtioenesxtapbirieliszation}
stabilization of
oscillation
Program
operation
SRTOESPEsTetitninpgut
Macro service request
End of first processing
End of macro service
Macro
service
STOP
(standby)
IDLE
(standby)
Interrupt request of
masked interrupt
HALT
(standby)
Note Only unmasked interrupt request
Remark Only external input of NMI is valid. The watchdog timer cannot be used to release the standby mode
(STOP/HALT/IDLE).
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