Intel MCS48 User Manual page 101

INSTRUCTION SET
JF1 address
Jump
If
Flag
1 Is
Set
(Not
in
8021, 8022)
111
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
flag
1
is
set to
one.
(PC0-7)-*-
addr
(PC)
= (PC)+2
If
F1
=
1
IF
F1=0
Example:
JF1IS1: JF1
FILBUF
JMP
address
Direct
Jump
Within
2K
Block
;JUMP
TO
'FILBUF'
;ROUTINE
IF
F1=1
l
10
a 9 a 8
°
100
a
7
a
6
a
5
a
4
a
3
a
2
a-|
a
This
is
a 2-cycle instruction. Bits
0-10
of the
program
counter
are replaced with the directly-specified
address.
The
setting of
PC
bit 11
is
determined by
the
most
recent
SELECT
MB
instruction.
(PC
8
-io)
(PC0-7H
(PCn)*
«-addr
8-10
-
addr 0-7
DBF
Example:
JMP SUBTOT
JMP
$-6
JMP
2FH
JUMP TO SUBROUTINE
'SUBTOT
JUMP TO
INSTRUCTION
SIX
LOCATIONS
BEFORE CURRENT LOCATION
JUMP TO ADDRESS
'2F'
HEX
JMPP
@A
Indirect
Jump
Within
Page
1011 0011
This
is
a 2-cycle
instruction.
The
contents
of
the
program
memory
location
pointed
to
by
the
accumulator
are substituted
for
the
'page'
portion of the
program
counter (PC
bits 0-7).
(PC0-7)*-
((A))
Example:
Assume
accumulator contains 0FH.
JMPPAG:
JMPP
@A
;JUMP
TO ADDRESS STORED
IN
.LOCATION
15 IN
CURRENT PAGE
JNC
address
Jump
If
Carry
Is
Not
Set
1110 0110
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
not
set,
that
is,
equals zero.
Mnemonics
copyright
Intel
Corporation
1976.
4-19