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CHAPTER 20 STANDBY FUNCTION
User’s Manual U15798EJ2V0UD
(c) Release by RESET input
When the RESET signal is input, HALT mode is released. And, as in the case with normal reset operation,
the program is executed after branch to the reset vector address.
Figure 20-3. HALT Mode Release by RESET Input
HALT instruction
Wait
(2
17
/f
X
: 13.1 ms)
Oscillation stabilization
wait status
Operation mode
HALT mode
Operation mode
Oscillation
stop
Clock
RESET
signal
Oscillation
Oscillation
Reset
period
Remarks 1.
f
X
: Main system clock oscillation frequency
2.
Values in parentheses are for operation with f
X
= 10 MHz.
Table 20-2. Operation After HALT Mode Release
Release Source
MK
××
PR
××
IE
ISP
Operation
Maskable interrupt request
0
0
0
×
Next address instruction execution
0
0
1
×
Interrupt servicing execution
0
1
0
1
Next address instruction execution
0
1
×
0
0
1
1
1
Interrupt servicing execution
1
×
×
×
HALT mode hold
Non-maskable interrupt request
—
—
×
×
Interrupt servicing execution
RESET input
—
—
×
×
Reset processing
×
: Don’t care
Caution In flash memory versions (
µ
PD78F0354, 78F0354Y), when the subclock multiplied by 4 is used,
set one NOP instruction immediately after HALT instruction execution to release HALT mode set
during servicing of an interrupt with a lower priority (setting is unnecessary for mask ROM
versions).