UPD784907 Datasheet, PDF (62/98 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLER

µPD784907, 784908
11. STANDBY FUNCTION
This function is to reduce the power consumption of the chip, and can be used in the following modes:
• HALT mode: Stops the operating clock of the CPU. This mode is used in combination with the normal operation
mode for intermittent operation to reduce the average power consumption.
• IDLE mode: Stops the entire system with the oscillator continuing operation. The power consumption in this
mode is close to that in the STOP mode. However, the time required to restore the normal program
operation from this mode is almost the same as that from the HALT mode.
• STOP mode: Stops the oscillator and thereby stops all the internal operations of the chip. Consequently, the
power consumption is minimized with only leakage current flowing.
These modes are programmable.
The macro service can be started from the HALT mode.
Figure 11-1. Standby Mode Status Transition
Wait for
oscillation
settling
Otimsceillealtaiopnsessettling
Program
operation
Macro service request
End of one operation
End of macro service
Macro
service
SRetESSTEOTPinput
STOP
(standby)
IDLE
(standby)
Request for masked interrupt
HALT
(standby)
Notes 1. INTW, INTP4, and INTP5 are applied when not masked.
2. Only unmasked interrupt request
3. When the watch clock is operating
Remark NMI is valid only for an external input. The watchdog timer cannot be used for the release of standby
(STOP, HALT, or IDLE mode).
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Data Sheet U11680EJ2V0DS00