Intel MCS48 User Manual page 100

INSTRUCTION SET
IN
A,P0
Input
of
Port
Data
to
Accumulator
(8021
,
8022
Only)
Same
as
INS
A,
BUS
except
no
RD
pulse generated.
INS
A,BUS
Strobed
Input
of
BUS
Data
to
Accumulator
000 100
This
is
a 2-cycle
instruction.
Data
present
on
the
BUS
port isjransferred (read)
to
the
accumulator
when
the
RD
pulse
is
dropped.
(Refer
to section
on
programming
memory
expansion
for details).
(A)—
(BUS)
INPBUS:
INS
A.BUS
Example:
JBb
address
Jump
If
Accumulator
Bit
is
Set (Not
in
8021, 8022)
;INPUT
BUS CONTENTS
;TO
ACC
b
2
b-|
b
1
10
a
7
a 6 a 5 a 4
a 3 a
2
a-|
a
This
is
a 2-cycle instruction.
Control passes
to
the
specified address
if
accumulator
bit
'b'
is
set
xo one.
b=0-7
(PC0-7)-*-
addr
(PC) = (PC)+2
If
Bb=1
If
Bb=0
Example:
JB4IS1:
JB4
NEXT
JC
address
Jump
If
Carry
Is
Set
;JUMP
TO
'NEXT
ROUTINE
;IF
ACC
BIT 4=1
1111 110
a
7
a
6
a
5
a 4 a
3
a
2 a^ a
This
is
a 2-cycle
instruction.
Control passes
to
the
specified
address
if
the carry
bit is
set to one.
(PC0-7)-*-
addr
(PC)
= (PC)+2
If
C=1
If
C=0
Example:
JC1:
JC
OVFLOW
JF0
address
Jump
If
Flag
Is
Set (Not
in
8021, 8022)
;JUMP
TO 'OVFLOW
ROUTINE
;IFC=1
10
11
110
a
7
a
6
a
5
a 4
|
a
3
a
2
a-j
a
This
is
a 2-cycle instruction.
Control passes
to
the
specified
address
if
flag
is
set to one.
(PC0-7)-*-
addr
(PC)
= (PC)+2
Example:
JF0IS1:
JF0
TOTAL
If
F0=1
If
F0=0
;JUMP
TO
TOTAL' ROUTINE
;IF
F0=1
Mnemonics
copyright
Intel
Corporation
1976.
4-18