Intel MCS48 User Manual page 107

INSTRUCTION SET
MOVD
A,Pp
Move
Port 4-7 Data
to
Accumulator
0000
1 1
pp
This
is
a 2-cycle
instruction.
Data on 8243
port
'p'
is
moved
(read) to
accumulator
bits 0-3.
Accumulator
bits
4-7 are zeroed.
(0-3)
(4-7)-
(Pp)
p=4-7
Note:
Bits 0-1 of the
opcode
are
used
to
represent
ports
4-7.
If
you
are coding
in
binary rather than
assembly
language, the
mapping
is
as
follows:
Bits
1
Port
4
1
5
1
6
1
1
7
Example:
INPPT5:
MOVD
A,P5
MOVD
Pp,A
Move
Accumulator Data
to Port
4-7
;MOVE PORT
5
DATA TO ACC
;BITS
0-3,
ZERO
ACC
BITS 4-7
00
11
1 1
pp
This
is
a
2-cycle
instruction.
Data
in
accumulator
bits 0-3
is
moved
(written) to
8243
port 'p'.
Accumulator
bits 4-7
are unaffected. (See
NOTE
above
regarding
port
mapping.)
(Pp)^-(A
_
3
)
p=4-7
Example:
Move
data
in
accumulator
to
ports 4
and
5.
OUTP45:
MOVD
P4,A
SWAP
A
MOVD
P5,A
MOVE ACC
BITS
0-3
TO PORT
4
EXCHANGE ACC
BITS
0-3
AND
4-7
MOVE ACC
BITS
0-3
TO PORT
5
MOVP
A,@A
Move
Current
Page
Data
to
Accumulator
10 10 00
11
The
contents
of
the
program
memory
location
addressed
by
the
accumulator
are
moved
to
the accumulator.
Only
bits
0-7
of
the
program
counter
are*
affected, limiting
the
program
memory
reference to the current page.
The
program
counter
is
restored following
this operation
(PC
_
7
)^
(A)
(A)^-
((PC))
Note: This
is
a
1-byte,
2-cycle
instruction.
If it
appears
in
location 255
of a
program
memory
page,
@A
addresses
a location
in
the following page.
Mnemonics
copyright
Intel
Corporation
1976.
4-25