LCD-IV--------------------------------------------------------------------
jumps (including interrupts).
CAL
is
a conditional instruction and executed only when the
Status F
IF
is
"1".
If
the Status F
IF
is
"0",
it
is
skipped and the
Status
F/F
changes
to
"1".
•
CALL
By
CALL instruction, subroutine jump to an address in any
bank and
page
is
performed.
Subroutine jump to any address can
be
implemented by the
subroutine jump
to
the
page
specified by
LPU
instruction in the
bank designated by the reversed-phase signal R
70.
This instruction
is
a macro instruction
of
LPU
and CAL
instructions, which
is
divided into two instructions
as
follows.
CALL
a·b
-LPU
a
CAL b
< Subroutine Jump
to
Bank "R70
",
a
Page
- b
Address>
CALL instruction
is
conditional because
of
characteristics
of
LPU
and CAL instructions and
is
executed when the Status
F/F
is
"1".
If
the Status F IF
is
"0",
the instruction
is
skipped and
the
Status F
IF
changes to
"1".
The examples
of
CALL instruc-
tion are shown in Figure 11.
/ (Page Part) \
Ban~a;
r---
Page Part
~
r--
Address Part
~
(PC)
(Modification)
~
~2
=
~,
=
~
: C
B3:
Bo
: B,
Bo
I
A3
:
Ao
: A, :
Ao
I
(PC
after
TBR
Instruction)
Figure 9 Modification
of
Program Counter
by
TBR Instruction
0.
______
0,
ROM
; : :
PC
~~k
[J
I I : r
~~
+ j : j
II
: I
:A!d')~
I : I
J
lllllllllll
ST1
I : : : : : : : : : :
ST2
ST3
: :
ST4
: :
Figure 10 Subroutine Jump Stacking Order
192
(PC +
1)
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