NEC mPD780973 Series Preliminary User's Manual page 248

(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 interrupt acknowledge is disabled, the next address instruction is executed.
Figure 20-2. HALT Mode Clear upon Interrupt Generation
Standby release
signal
Operating mode
Clock
Remarks 1. The broken line indicates the case when the interrupt request which has cleared the standby
mode is acknowledged.
2. Wait times are as follows:
• When vectored interrupt service is carried out
• 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.
248
CHAPTER 20 STANDBY FUNCTION
HALT instruction
HALT mode
Oscillation
Wait
Wait Operating mode
: 8 to 9 clocks