RX8804CE
Page - 27
ETM59E-05
8.3.4. Wakeup Timer Interrupt Interval (example)
Table 51 Wakeup Timer Interrupt Interval
Preset Value
Source clock
4096 Hz
TSEL1,0 = 0,0
64 Hz
TSEL1,0 = 0,1
"Second" update
TSEL1,0 = 1,0
"Minute" update
TSEL1,0 = 1,1
0
−
−
−
−
1
244.14
s
15.625 ms
1 s
1 min
2
488.28
s
31.25 ms
2 s
2 min
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
41
10.010 ms
640.63 ms
41 s
41 min
82
20.020 ms
1.281 s
82 s
82 min
128
31.250 ms
2.000 s
128 s
128 min
192
46.875 ms
3.000 s
192 s
192 min
205
50.049 ms
3.203 s
205 s
205 min
320
78.125 ms
5.000 s
320 s
320 min
410
100.10 ms
6.406 s
410 s
410 min
640
156.25 ms
10.000 s
640 s
640 min
820
200.20 ms
12.813 s
820 s
820 min
1229
300.05 ms
19.203 s
1229 s
1229 min
1280
312.50 ms
20.000 s
1280 s
1280 min
1920
468.75 ms
30.000 s
1920 s
1920 min
2048
500.00 ms
32.000 s
2048 s
2048 min
2560
625.00 ms
40.000 s
2560 s
2560 min
3200
0.7813 s
50.000 s
3200 s
3200 min
3840
0.9375 s
60.000 s
3840 s
3840 min
4095
0.9998 s
63.984 s
4095 s
4095 min
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
16777215
4096 s
3 days,49 min.4 s
194 days
32 years
8.3.5. Wakeup Timer Interrupt Timing Chart
TIE bit
/INT output
TF bit
Event occurs
TE bit
tRTN
tRTN
tRTN
period
period
period
tRTN
period
"
1
"
"
0
"
"
1
"
"
0
"
Hi-Z
"
L
"
"
1
"
"
0
"
Even when the TF
bit is cleared to zero,
the /INT status does
not change.
Even when the TE bit
is cleared to zero, /INT
remains low during the
tRTN time.
Operation of fixed-cycle timer
When the TE bit value changes from
"0"
to "1"
the fixed-cycle timer function starts.
The counter always starts counting down from the preset value when the TE value changes from "0" to "1".
RTC internal operation
Write operation via I
2
C
Fixed-cycle timer starts
Fixed-cycle timer stops
(1)
(1)
(2)
• • •
001
h
→
000
h
(3)
(4)
(5)
"
1
"
(6)
(7)
(7)
(7)
(8)
(9)
Figure 17 Wakeup Timer Timing Chart