Intel MCS48 User Manual page 368

8279/8279-5
1
1
1
1
2
1
1
2
1
17 2
1
17 18
1st
entry
2nd
entry
16th entry
17th entry
18th entry
LEFT ENTRY
MODE
(AUTO INCREMENT)
Right Entry
Right entry
is
the
method
used by most
electronic
calculators.
The
first
entry
is
placed
in
the
right
most
display character.
The
next entry
is
also
placed
in
the right
most
character
after
the display
is
shifted
left
one
character.
The
left
most
character
is
shifted
off
the
end
and
is lost.
14 15
0-«-Display
RAM
14 15-«
14 15
14 15
15 16
14 15
15 16
14 15
15 16
-Display
RAM
Address
1
2
1st
entry
2 3
2nd
entry
3
4
3rd entry
1
6th entry
1
2
17th entry
18th entry
1
15
1
1
2
1
2
1
2 3
13 14 15
14 15 16
Address
1
2
2 3
2
3
3~T^
14 15
15
j
16 17
15
1
16 17 18
RIGHT
ENTRY MODE
(AUTO INCREMENT)
Note
that
now
the display position
and
register
address
do
not
correspond. Consequently,
entering a
character
to
an
arbitrary position
in
the
Auto Increment
mode may
have
unexpected
results.
Entry
starting
at
Display
RAM
address
with sequential entry
is
recommended.
Auto Increment
In
the
Left
Entry
mode, Auto
Incrementing causes the
address
where
the
CPU
will
next write to
be incremented
by
one and
the character appears
in
the next
location.
With
non-Auto
Incrementing
the entry
is
both
to
the
same
RAM
address and display
position.
Entry
to
an
arbitrary
address
in
the
Auto Increment
mode
has no undesirable
side effects
and
the
result
is
predictable:
1st
entry
2nd
entry
Command
10010101
3rd entry
4th entry
1
2 3 4
5 6
7-
1
Display
RAM
Address
1
2 3
4
5
6 7
1
2
1
2
3
4 5 6
7
1
2
Enter next
at
Location 5 Auto
Increment
1
2
3 4 5 6
7
1
2 3
1
2 3 4 5 6 7
1
I
2
I I I I
3
I
4
LEFT
ENTRY MODE
(AUTO INCREMENT)
In
the Right Entry mode, Auto
Incrementing
and non
Incrementing have
the
same
effect as
in
the
Left
Entry
except
if
the
address sequence
is
interrupted:
1st
entry
2nd entry
Command
10010101
3rd entry
4th entry
1
2 3 4 5 6
7
0-
1
2 3
4
5
6
7
1
[
I
1
2
2 3 4 5 6
7
1
|
1
2
-
Display
RAM
Address
Enter next
at
Location 5
Auto
Increment
3 4
5 6 7
1
2
I I
3
1
2
4
5 6 7
1
2
3
3
4
1
2
RIGHT
ENTRY MODE
(AUTO INCREMENT)
Starting
at
an arbitrary location operates
as
shown
below:
1
2 3 4 5
6 7
-«-
Display
Command
10010101
1st
entry
2nd
entry
8th entry
9th entry
RAM
Address
Enter next
at
Location 5 Auto Increment
1
2 3
4
5
6
7
~r
|
1
|
2 3 4 5 6
7
1
j
1
]
2
4
5 6 7 8
1
2 3
5 6 7
8
9 2 3
J4
RIGHT
ENTRY MODE
(AUTO INCREMENT)
8-78 00742A