JPO
Chapter
3.
Instruction
Set
JUMP
IF
PARITY
ODD
Parity
is
odd if
the
byte
in
the accumulator has an odd number
of
one bits. The parity flag
is
set to zero
to
indicate this
condition.
The J
PO
instruction tests the setting
of
the
parity flag. If the parity flag
is
reset to zero, program execution
resumes
at
the address specified
in
the
J
PO
instruction.
If
the flag
is
set to one, execution continues with the
next sequential instruction.
Opcode
Operand
JPO
address
The address
may
be
specified as a number, a label,
01"
an
expre,,>ion. The as'>embler invert, the high and low
address bytes when
it
assembles the instruction.
The J
PO
and J
PE
(jump
if
parity even)
instruction~
are especi,lIly u,ciul tor tf'qing the parity
of
input data.
However,
the
IN
instruction does not set any
of
the condition
flag'>.
The flag,
Cdn
be
,et
by
adding
OOH
to the
contents
of
the
accumulator.
1
1
1
Cycles:
States:
Addressing:
Flags:
Example:
0 0
0
I
0
low addr
high
addr
3
(2
or 3 on 8085)
10
(7
or 10 on 8085)
immediate
none
This example shows three different
but
equivalent
rTlethod,>
fur jumping to one
of
two
poinh
in
a
prograrTl
hd'cd
upon whether or not the Sign bit
of
a number
is
'>et.
A<;sume
that the hyte to
be
te'>tcd
i~
the C
regi<;ter.
Label Code Operand
ONE:
MOV
A,C
ANI
80H
JZ
PLUS
jNZ
MINUS
TWO:
MOV
A,C
RLC
jNC
PLUS
jMP
MINUS
THREE:
MOV
A,C
ADI
0
JM
MINUS
PLUS: ;SIGN BIT RESET
MINUS:
;SIGN BIT
SET
3-31
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