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--------------------------------------------------------------------LCD-IV
I
Becomes halt state after executing RED
instruction and the halt is maintained
.--__ L V_I _....,15
until a prescaler overflow signal is issued.
L-~R~E~D
__
r_------~--~.
LVI
0
f-L
TO
BR
.-4
The LCD-IV returns from halt state by a pre-
scaler overflow signal and operation restarts
from LVI instruction. With this program,
unless the Do terminal is set to "0", internal
halt state Occurs repeatedly.
Figure 33 Program example in the Internal Halt Mode
Program~
V---------
n +1
~
Counter
~
_ _ _ ..... " - - -
_ _ _ _ _ _ _ _ _ _
"-n+2--A--.-
ROM
--::-v
n +
1
Address
~
_ _ _ _ _ _ ___
_________ - J
x
n+2 X~
_______________ _
ROM
-::J\
~r
\'-____
n_+_1 ___
--JX'-____ . . . . . .
~
- - \ - - - - - H a l t
State~
Halt Signal
- - - - -
16
Instructions
Prescaler
Overflow------------·
- - - - - - - - - - - - - - - -
Signal
Figure 34 Internal Halt Timing Chart
• CRYSTAL OSCILLATION CIRCUIT FOR TIMER
The user can specify by the "MASK OPTION LIST"
whether or not the timer crystal should be externally
attached. By externally attaching a crystal oscillator of
32.768kHz to the DI4/XO and DIS/XI terminals, maxi·
mum 1 second of timer interruption cycle is possible
setting the prescaler clock to 1,024Hz.
No.
Halt state
1 External halt
2 External halt
3 I nternal and
external halt
D
I4
/XO
LCD-IV
D15/ XI
Rd
R
With or without
timer crystal
Externally attached
crystal (32.768 kHz)
(Without crystal)
Internal clock of LSI
Externally attached
crystal (32.768 kHz)
c.
(NOTE)
The crystal oscillator, resistor R, Rd and load
capacitor C
I
and C
a
should be placed as close
as
possible to the LCD-IV. Induction of ex-
ternal noise to D
14
/XO and D15/XI may
disturb normal oscillation.
This circuit is the example of the typical use.
As the oscillation characteristics is not guar-
anteed, please consider and examine the
circuit constants carefully on your application.
Figure 35 Crystal Oscillator Circuit
0 14 ,0 15 (XO, XI)
Function
terminals
Terminals for attaching
Prescaler clock is set to 1,024 Hz and the over-
crystal. Cannot be used
flow signal to 16 Hz. Up to 1 second can be set
as general I/O.
as the timer interruption cycle.
The prescaler clock becomes 100 kHz type,
Used as general I/O
and the timer interruption cycle can be set to
maximum 97.66 Hz.
Prescaler clock is set to 1,024 Hz and the over·
Terminals for attaching
flow signal to 16 Hz. This signal performs the
crystal. Cannot be used
LCO·IV return from internal halt.
as general I/O.
(Return from external halt is not possible by the
prescaler overflow signaL)
211
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