UPD784915B Datasheet, PDF (57/86 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLERS

µPD784915B, 784916B
4.2 Standby Function
The standby function serves to reduce the power dissipation of the chip and is used in the following modes:
Mode
Function
HALT mode
STOP mode
Low power dissipation mode
Low power dissipation HALT mode
Stops operating clock of CPU. Reduces average power dissipation when
used in combination with normal mode for intermittent operation
Stops oscillator. Stops all internal operations of chip to minimize current
dissipation to leakage current only
Stops main system clock with subsystem clock used as system clock. CPU
can operate with subsystem clock to reduce power dissipation
Standby function in low power dissipation mode. Stops operating clock of
CPU. Reduces power dissipation of overall system
These modes are programmable.
The macro service can be started in the HALT mode.
Figure 4-4. Status Transition of Standby Mode
Low power
dissipation mode
(subsystem
clock operation)
Sets low power dissipation mode
Restores normal operation
End ^{of oscilation stabilization period}
Waits for
stabilization
of oscillation
Normal
operation
EnEdnoMdf ^{aomcfaroocnrseoepsrveroircvceiecrseesqinugest}
Macro
service
Low power
dissipation
HALT mode
(standby)
STOP mode
(standby)
HALT mode
(standby)
Unmasked
interrupt request
Notes 1. NMI input means starting NMI by NMI pin input, watch interrupt, or key interrupt input.
2. Unmasked interrupt request
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