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RX
8564 LC
13.2.2. Related registers for function of timer interrupts.
Address [h]
01
0E
Timer control
0F
Before starting the fixed-cycle timer interrupt function each time, be sure to write a value (preset value/Reg-0F[h])
as the timer's down counter value (when TE = "0").
(Note) Note with caution that the preset value must be set or reset to enable correct operation.
Before entering operation settings, we recommend first clearing the TE bit to "0" and then clearing the TF and TIE
bits to "0" in that order, so that all control-related bits are zero-cleared (= set to operation stop mode) to prevent
hardware interrupts from occurring inadvertently while entering settings.
1) TI / TP bit ( Interrupt Signal Output Mode Select. Interrupt / Periodic )
When a fixed-cycle timer interrupt event occurs, this bit selects whether to end the operation after one
iteration or to repeat the operation.
TI / TP
Write / Read
2) TD1, TD0 bits ( Timer countDown interval select 1, 0 )
These bits specify the fixed-cycle timer interrupt function's countdown period (source clock).
Four different periods can be selected via combinations of these two bit values.
TD1, TD0
W / R
1) During repeated interrupt mode (TI/TP bit = "1"), the auto recovery time tRTN (when the /INT pin is
switched from low level to Hi-Z) varies according to the source clock and preset value, as shown above.
2) The countdown when a 1-Hz source clock has been selected is linked to updating of the internal clock's
seconds setting.
Since the internal clock is linked to updating of the seconds setting, if the timer is started at a clock
time of 0.9 seconds, the first countdown will occur only 0.1 second later. (The second and subsequent
countdowns will occur at the correct time interval.)
2) The countdown when a 1/60-Hz source clock has been selected is linked to updating of the internal
clock's minutes setting.
Since the internal clock is linked to updating of the minutes setting, if the timer is started at a clock
time of 50 seconds, the first countdown will occur only 10 seconds later. (The second and subsequent
countdowns will occur at the correct time interval.)
Function
bit 7
Control 2
0
TE
Timer
128
Data
[Level interrupt mode]
0
Fixed-cycle timer interrupt function operates one time only
) Another operation can be set via various bit settings.
[Repeated interrupt mode]
1
Fixed-cycle timer interrupt function operates repeatedly
TD1
TD0
( bit 1 )
( bit 0 )
0
0
4096 Hz
0
1
1
0
1
1
1/60 Hz
bit 6
bit 5
bit 4
0
TI / TP
64
32
16
Description
Source clock
/ 244.14 s cycle
64 Hz
/ 15.625 ms cycle
/ Updated per second
1 Hz
/ Updated per minute
Page
20
bit 3
bit 2
bit 1
AF
AIE
TF
TD1
8
4
2
( )
/INT auto recovery time tRTN
during repeated interrupt mode
Preset value
Preset value
n = 1
122
s
7.813 ms
15.625 ms
15.625 ms
15.625 ms
15.625 ms
15.625 ms
ETM12E-01
bit 0
TIE
TD0
1
1 < n
244
s
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