248
CHAPTER 20 STANDBY FUNCTION
(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
HALT instruction
Wait
Wait
Operating mode
HALT mode
Operating mode
Oscillation
Clock
Standby release
signal
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
: 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.
Summary of Contents for mPD780973 Series
Page 2: ...2 MEMO ...
Page 66: ...66 MEMO ...
Page 98: ...98 MEMO ...
Page 138: ...138 MEMO ...
Page 164: ...164 MEMO ...
Page 182: ...182 MEMO ...
Page 204: ...204 MEMO ...
Page 244: ...244 MEMO ...
Page 262: ...262 MEMO ...
Page 278: ...278 MEMO ...
Page 290: ...290 MEMO ...