UPD78F0138 NEC, UPD78F0138 Datasheet - Page 231

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

(1) Watch timer
(2) Interval timer
Remark
Remark
2
2
2
2
2
2
2
2
2
2
2
2
4
5
13
14
4
5
6
7
8
9
10
11
/f
/f
/f
/f
/f
/f
/f
/f
When the X1 input clock or subsystem clock is used, interrupt requests (INTWT) are generated at preset
intervals.
Interrupt requests (INTWTI) are generated at preset time intervals.
/f
/f
/f
/f
W
W
W
W
W
W
W
W
W
W
W
W
f
f
f
f
f
f
X
XT
W
X
XT
W
Interrupt Time
: X1 input clock oscillation frequency
: X1 input clock oscillation frequency
Interval Time
: Watch timer clock frequency
: Watch timer clock frequency
: Subsystem clock oscillation frequency
: Subsystem clock oscillation frequency
Table 9-1. Watch Timer Interrupt Time
Table 9-2. Interval Timer Interval Time
488
977
0.25 s
0.5 s
488
977
1.95 ms
3.91 ms
7.81 ms
15.6 ms
31.3 ms
62.5 ms
When Operated at f
When Operated at f
CHAPTER 9 WATCH TIMER
µ
µ
µ
µ
User’s Manual U16228EJ2V0UD
s
s
s
s
XT
XT
= 32.768 kHz
= 32.768 kHz
205
410
0.105 s
0.210 s
205
410
820
1.64 ms
3.28 ms
6.55 ms
13.1 ms
26.2 ms
When Operated at f
When Operated at f
µ
µ
µ
µ
µ
s
s
s
s
s
X
X
= 10 MHz
= 10 MHz
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