RNC
RNZ
Chapter
3.
Instruction
Set
RETURN
IF NO
CARRY
The RNC instruction tests the cJrry flag. If the flag
is
set
to
zero
to
indicate
that
there has been no cJrry, the
in'>truction pops
two
bytes
off
the ctack and places them
in
the program
counter.
Program
execution
resumes
at
the
new address
in
the program
counter.
If the flag
is
one, program execution simply
continues
with the next
sequential
in<;truction.
Opcode
Operand
RNC
Operand,> are
not
permitted
with the RNC instruction.
o
Cycles:
State',:
Addressing:
Flag'>:
Example:
o 0 0
0\
or
3
5
or
11
(6 or 12 on 8085)
register indirect
none
For
the
sake
of
brevity, an example
i',
given for the RET instruction
but
not for each
of
its closely related
varian ts.
RETURN
IF NOT
ZERO
The RNZ instruction tests the zero flag.
If
the flag
is
set
to
zero
to
indicate
that
the
contents
of
the
accumulator
are
other
than
lero,
the instruction pops two bytes
off
the stack and places them
in
the program
counter.
Pro-
gram
execution
resume, at the new address
in
the program
counter.
If
the flag
is
'>et
to one, program
execution
,imply
continue,
with the next '>equential
imtruction.
Opcode
Operand
RNZ
Operand,
are not
permitted
with the RNZ instruction.
Example:
o 0 0 0 0
01
Cycles:
State',:
Addressing:
Flags:
or 3
5
or
11
(6 or 12 on 8085)
register indirect
none
For the
,>ake
of
brevity, an example
i',
given for the RET instruction
but
not
for each
of
its closely related
varian ts.
3-51
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