Intel MCS48 User Manual page 232

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a.
Basic
Input
Mode
X
IDC
\
/
X
b.
Basic Output
Mode
N
/
DATA
BUS
TIMING
IS
SHOWN
IN
FIGURE
7.
Figure
14. Basic I/O Timing Waveform
•wp-
"".-jx
z>c:r:
>:
LOAD COUNTER FROM
CLR
I
2
I
TIMER OUT
(SQUARE WAVE)
NOTE
1:
THE TIMER OUTPUT
IS
PERIODIC
IF
IN
AN AUTOMATIC
RELOAD MODE
(M
1
MODE
BIT=
1)
Figure
15.
Timer Output
Waveform Countdown
from
5 to
1
6-80