Zilog Z8F0130 User Manual
Page 128
eZ8
™
CPU Core
User Manual
UM012820-0810
CALL Instruction
113
Attributes
Escaped Mode Addressing
Using Escaped Mode Addressing, address mode IR specifies a working
register. If the destination address is prefixed by
Eh
(
1110b
), a working
register is inferred. For example, if Working Register R12 (
Ch
) is the pre-
ferred destination operand, use
ECh
as the destination operand in the Op
Code. To access registers with addresses
E0h
to
EFh
, either set the Work-
ing Group Pointer,
RP[7:4]
, to
Eh
or use indirect addressing.
Sample Usage
If the contents of the Program Counter are
1A47h
and the contents of the
Stack Pointer are
3002h
, the following statement causes the Stack Pointer
to be decremented to
3000h
,
1A4Ah
(the address following the CALL
instruction) to be stored in Program Memory locations
3001h
and
3000h
,
and the Program Counter to be loaded with
3521h
:
CALL 3521h
Object Code: D6 35 21
The Program Counter now points to the address of the first statement in
the called procedure to be executed. The flags are unaffected.
If the contents of Program Counter are
1A47h
and the contents of the
Stack Pointer are
3724h
, the contents of Register A4h are
34h
, and the
contents of the Register Pair
34h
are
3521h
, the following statement
causes the Stack Pointer to decrement to
3722h
, stores
1A4Ah
(the
address following the CALL instruction) in Program Memory locations
3723h and 3722h, and loads the Program Counter with
3521h
:
Mnemonic Destination
Op
Code
(Hex)
Operand 1 Operand 2 Operand 3
CALL
@RR1
D4
RR1
—
—
CALL
DA
D6
DA[15:8]
DA[7:0]
—