Halt Mode Release By Interrupt Request Generation - NEC mPD780208 Subseries User Manual

(2) HALT mode release
The HALT mode can be released by the following four sources.
(a) Release by unmasked interrupt request
When an unmasked interrupt request is generated, the HALT mode is released. If interrupt request
acknowledgment is enabled, vectored interrupt servicing is carried out. If disabled, the instruction
at the next address is executed.
Figure 17-2. HALT Mode Release by Interrupt Request Generation
Standby
release signal
Clock
Remarks 1. The broken line indicates the case when the interrupt request which has released the
2. Wait time will be as follows.
(b) Release by non-maskable interrupt request
When a non-maskable interrupt request is generated, the HALT mode is released and vectored
interrupt servicing is carried out regardless of whether interrupt request acknowledgment is enabled
or disabled.
However, a non-maskable interrupt request is not generated during subsystem clock operation.
(c) Release by unmasked test input
When an unmasked test signal is input, the HALT mode is released and the instruction at the next
address to the HALT instruction is executed.
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CHAPTER 17 STANDBY FUNCTION
Interrupt request
HALT
instruction
Operating
HALT mode
mode
standby status is acknowledged.
• When vectored interrupt servicing is carried out:
• When vectored interrupt servicing is not carried out: 2 to 3 clocks
User's Manual U11302EJ4V0UM
Wait
Wait Operating mode
Oscillation
8 to 9 clocks