Rx − 8564 lc – Epson RX-8564LC User Manual
Page 23
RX
−
8564
LC
Page
−
20
ETM12E-01
13.2.2. Related registers for function of timer interrupts.
Address [h]
Function
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
01
Control 2
0
×
0
TI
/
TP
AF
TF
AIE
TIE
0E
Timer control
TE
Ч
Ч
Ч
Ч
Ч
TD1
TD0
0F
Timer
128
64
32
16
8
4
2
1
∗
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
Data
Description
0
[Level interrupt mode]
Fixed-cycle timer interrupt function operates one time only
(
∗
)
∗
)
Another operation can be set via various bit settings.
Write / Read
1
[Repeated interrupt mode]
Fixed-cycle timer interrupt function operates repeatedly
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.
/INT auto recovery time tRTN
during repeated interrupt mode
TD1,
TD0
TD1
(
bit 1
)
TD0
(
bit 0
)
Source clock
Preset value
n
=
1
Preset value
1
<
n
0
0
4096 Hz
/ 244.14
µ
s cycle
122
µ
s
244
µ
s
0
1
64 Hz
/ 15.625
ms cycle
7.813
ms
15.625
ms
1
0
1
Hz
/ Updated per second
15.625
ms
15.625
ms
W / R
1
1
1/60
Hz
/ Updated per minute
15.625
ms
15.625
ms
∗
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.)