NEC mPD789026 Subseries, User Manual

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CHAPTER 11 STANDBY FUNCTION
User's Manual U11919EJ3V0UM00
168
11.1.2 Standby function control register
The wait time after the STOP mode is released upon interrupt request until the oscillation settles is controlled
with the oscillation settling time select register (OSTS).
OSTS is set with an 8-bit memory manipulation instruction.
RESET input sets OSTS to 04H. However, the oscillation settling time after RESET input is 2
15
/f
X
, instead of
2
17
/f
X
.
Figure 11-1. Oscillation Settling Time Select Register Format
OSTS2
0
0
1
0 0 0 0 0 OSTS2 OSTS1 OSTS0 OSTS
R/W
FFFAH 04H R/W
7 6 5 4 3 2 1 0
OSTS1
0
1
0
2
12
/f
X
2
15
/f
X
2
17
/f
X
(819 s)
µ
(6.55 ms)
(26.2 ms)
OSTS0
0
0
0
Setting prohibited
Symbol Address
After Reset
Oscillation Settling Time Selection
Other than above
Caution The wait time after the STOP mode is released does not include the time from STOP mode
release to clock oscillation start ("a" in the figure below), regardless of release by RESET input
or by interrupt generation.
V
SS
a
STOP Mode Release
X1 Pin Voltage
Waveform
Remarks 1. f
X
: System clock oscillation frequency
2. The parenthesized values apply to operation at f
X
= 5.0 MHz.