Intel MCS48 User Manual page 136

APPLICATION
EXAMPLES
+5V
GND
Vcc
V
S
S
XTAL1
8049
8048
8748
8021*
8035
8039
8022*
ALE
PROG
DISPLAY
AND/OR
KEYBOARD
ARRAY
This
is
most
useful
when
the outputs
of
the
74LS164
eight-bit
shift register
will
be used
to
scan
a display and/or keyboard.
In this
case an
ANLD
P7,
A
with
A = 0FFH
can be used
to
load
the
initial
"1
"
and an
ANLD
P6,
A
with
A =
0FEH
can be used
to
move
it
down
the
shift register.
QA
QB QC
QD QE QF QG QH
74 LSI 64
(14)
"PIN
NUMBERS ARE
DIFFERENT
FOR
8021,
8022
ADDING OUTPUT FOR KEYBOARD/DISPLAY SCANNING
5-16