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CHAPTER 20 STANDBY FUNCTION
User’s Manual U19780EJ2V0UD
543
(2) HALT mode release
The HALT mode can be released by the following two sources.
(a) Release by unmasked interrupt request
When an unmasked interrupt request is generated, the HALT mode is released. If interrupt acknowledgment
is enabled, vectored interrupt servicing is carried out. If interrupt acknowledgment is disabled, the next
address instruction is executed.
Figure 20-3. HALT Mode Release by Interrupt Request Generation
HALT
instruction
Wait
Note 1
Normal operation
HALT mode
Normal operation
Oscillation
High-speed system clock,
internal high-speed oscillation clock,
or subsystem clock
Note 2
Status of CPU
Standby
release signal
Interrupt
request
Notes 1.
The wait time is as follows:
• When vectored interrupt servicing is carried out:
11 or 12 clocks
• When vectored interrupt servicing is not carried out: 4 or 5 clocks
2.
The 78K0/KB2-A is not provided with a subsystem clock.
Remark
The broken lines indicate the case when the interrupt request which has released the standby
mode is acknowledged.