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(2) HALT mode clear
The HALT mode can be cleared with the following four types of sources.
(a) Clear upon unmasked interrupt request
The HALT mode is cleared when the unmasked interrupt request is generated. If interrupt request
acknowledge is enabled, vectored interrupt service is carried out. If disabled, the next address instruction
is executed.
Standby
Release Signal
Remarks 1. The broken line indicates the case when the interrupt request which has cleared the standby
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(b) Clear upon non-maskable interrupt request
The HALT mode is cleared and vectored interrupt service is carried out when the non-maskable interrupt
request is generated whether interrupt request acknowledge is enabled or disabled.
(c) Clear upon unmasked test input
The HALT mode is cleared when the unmasked test signal inputs and the next address instruction of the
HALT instruction is executed.
486
CHAPTER 20 STANDBY FUNCTION
Figure 20-2. HALT Mode Clear upon Interrupt Request Generation
HALT
Instruction
Operating
Mode
Clock
status is acknowledged.
2. Wait time will be as follows:
• When branched to the vector
• When not branched to the vector : 4.5 to 5.5 clocks
Interrupt
Request
Wait
HALT Mode
Wait
Oscillation
: 16.5 to 17.5 clocks
Operating
Mode
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