NEC uPD78056Y User Manual

Page 531

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CHAPTER 23 STANDBY FUNCTION

STOP
Instruction

Wait

(Time set by OSTS)

Oscillation Stabilization

Wait Status

Operating
Mode

Oscillation

Operationg
Mode

STOP Mode

Oscillation Stop

Oscillation

Standby
Release Signal

Clock

Interrupt
Request

(2) STOP mode release

The STOP mode can be cleared with the following three types of sources.

(a) Release by unmasked interrupt request

When an unmasked interrupt request is generated, the STOP mode is cleared. If interrupt request

acknowledge is enabled after the lapse of oscillation stabilization time, vectored interrupt service is carried

out. If interrupt request acknowledge is disabled, the next address instruction is executed.

Figure 23-4. STOP Mode Release by Interrupt Request Generation

Remark

The broken line indicates the case when the interrupt request which has cleared the standby

status is acknowledged.

(b) Release by unmasked test input

When an unmasked test signal is input, the STOP mode is cleared. And after the lapse of oscillation

stabilization time, the instruction at the next address of the STOP instruction is executed.

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