Zilog Z8F0130 User Manual

Page 128

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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]

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