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Zilog Z86193 User Manual

Page 165

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Z8

®

CPU

User Manual

UM001604-0108

Instruction Description

158

Add

Syntax

ADD dst, src

Instruction Format

Operation

dst

dst + src

The source operand is added to the destination operand. Two’s complement addition is
performed. The sum is stored in the destination operand. The contents of the source oper-
and are not affected.

Address modes R or IR can be used to specify a 4-bit Working Register. In this format, the
source or destination Working Register operand is specified by adding

1110b

(

Eh

) to the

high nibble of the operand. For example, if Working Register R12 (CH) is the destination
operand, then

ECh

is used as the destination operand in the Op Code.

Cycles

OPC (Hex)

Address Mode

dst

src

OPC

dst src

6

02

r

r

6

03

r

lr

OPC

src

dst

10

04

R

R

10

05

R

IR

OPC

dst

src

10

06

R

IM

10

07

IR

IM

Flags Description
C

Set if there is a carry from the most significant bit of the result;
cleared otherwise

Z

Set if the result is zero; cleared otherwise

S

Set if the result is negative; cleared otherwise

V

Set if an arithmetic overflow occurs, that is, if both operands are
of the same sign and the result is of the opposite sign; cleared
otherwise

D

Always cleared

H

Set if there is a carry from the most significant bit of the low order
four bits of the result; cleared otherwise

E

src

or

E

dst

Note: