Intel MCS48 User Manual page 103

INSTRUCTION SET
JTF
address
Jump
If
Timer
Flag
Is
Set
000
1
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 timer
flag
is
set to one,
that
is,
the timer/counter
register
has overflowed.
Testing the timer
flag
resets
it
to
zero. (This
overflow
initiates
an
interrupt service
sequence
if
the timer-overflow
interrupt
is
enabled.)
(PC
_
7
)-*-addr
(PC)
= (PC)+2
If
TF=1
If
TF=0
;
JUMP TO
TIMER'
ROUTINE
;IFTF=1
Example: JTF1:
JTF
TIMER
JT0
address
Jump
If
Test
Is
High (Not
in
8021
00
11
110
a
7
a
6
a
5
a
4
a 3 a 2
a-|
a
This
is
a 2-cycle
i
specified
address
nstruction.
Control
if
the
test
signal
passes
to
the
s
high
(=1).
(
p
Co-7)-*-
addr
(PC)
= (PC)+2
If
T0=1
If
T0=0
Example: JT0HI:
JT0
53
;JUMP
TO LOCATION
53
DEC
;IFT0=1
JT1 address
Jump
If
Test
1 Is
High
10
1
110
a
7
a
6
a
5
a
4
a
3
a
2
a-|
a
This
is
a 2-cycle
i
specified
address
nstruction.
Control
if
the
test
1
signal
passes
to
the
is
high
(=1).
(PC
-7)-«-addr
(PC) =
(PC)+2
If
T1=1
If
T1=0
Example: JT1HI: JT1
COUNT
JZ
address
Jump
If
Accumulator
Is
Zero
;JUMP
TO 'COUNT
ROUTINE
;IFT1=1
1100
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
accumulator
contains
all
zeros
at
the time
this
instruction
is
executed.
(PC
-
7
)-*-addr
(PC)
= (PC)+2
Example:
JACCO:
JZ
0A3H
If
A=0
If
A#0
;JUMP
TO LOCATION
'A3'
HEX
;IF
ACC
VALUE
IS
ZERO
Mnemonics
copyright
Intel
Corporation
1976.
4-21