UPD78F1154GK-GAK-AX NEC, UPD78F1154GK-GAK-AX Datasheet - Page 65

• Manufacturer Part Number: UPD78F1154GK-GAK-AX
• Description: 16BIT MCU, 128K FLASH, 8K RAM, SMD
• Manufacturer: NEC

Specifications of UPD78F1154GK-GAK-AX

• Controller Family/series: UPD78F
• No. Of I/o's: 70
• Ram Memory Size: 8192Byte
• Cpu Speed: 20MHz
• No. Of Timers: 9
• No. Of: RoHS Compliant
• Core Size: 16bit
• Program Memory Size: 128KB
• Oscillator Type: External, Internal

9. STANDBY FUNCTION
available.
The standby function is designed to reduce the operating current of the system. The following two modes are
• HALT mode: Stops the operating clock of the CPU.
• STOP mode: Stops oscillation of the main system clock.
The standby function uses the following two types of registers.
(1) Oscillation stabilization time counter status register (OSTC)
(2) Oscillation stabilization time select register (OSTS)
This register indicates the counting status of the oscillation stabilization time counter of the X1 clock.
The X1 clock oscillation stabilization time can be checked in the following case,
This register is used to select the oscillation stabilization time of the X1 clock when the STOP mode is
released.
If the X1 clock is selected as the CPU clock, the CPU waits for the time set by OSTS after the STOP mode is
released.
If the internal high-speed oscillation clock is selected as the CPU clock, confirm that the oscillation stabilization
time has elapsed after the STOP mode was released, by using OSTC. OSTC can be used to check the time
set in advance by OSTS.
• If the X1 clock starts oscillation while the internal high-speed oscillation clock or subsystem clock is being
• If the STOP mode is entered and then released while the internal high-speed oscillation clock is being used
used as the CPU clock.
as the CPU clock with the X1 clock oscillating.
operation mode for intermittent operation, the average current consumption can be decreased.
stopped, so that the power consumption can be reduced more than in the HALT mode.
Main system clock operation
Interrupt
request
Main system clock
oscillation stops.
STOP mode
STOP instruction
Preliminary Product Information U17892EJ2V0PM
Figure 9-1. Standby Function
Interrupt request
HALT instruction
By using this mode in combination with the normal
All operations using the main system clock are
Clock supply to CPU stops.
Oscillation continues.
HALT mode
78K0R/KF3
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