NEC NEC PD78081(A), User Manual

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CHAPTER 13 STANDBY FUNCTION
HALT
Instruction
Wait
Standby
Release Signal
Operating
Mode
Clock
HALT Mode Wait
Oscillation
Operating Mode
(2) HALT mode clear
The HALT mode can be cleared with the following three types of sources.
(a) Clear upon unmasked interrupt request
An unmasked interrupt request is used to clear the HALT mode. If interrupt acknowledge is enabled,
vectored interrupt service is carried out. If disabled, the next address instruction is executed.
Figure 13-2. HALT Mode Clear upon Interrupt Generation
Remarks 1. The broken line indicates the case when the interrupt request which has cleared the standby
status is acknowledged.
2. Wait time will be as follows:
• When vectored interrupt service is carried out: 8 to 9 clocks
• When vectored interrupt service is not carried out: 2 to 3 clocks
(b) Clear upon non-maskable interrupt request
The HALT mode is cleared and vectored interrupt service is carried out whether interrupt acknowledge
is enabled or disabled.