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Zilog EZ80F916 User Manual

Page 59

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eZ80

®

CPU

User Manual

UM007715-0415

Addressing Modes

50

Indexed Addressing
In this mode of addressing, a byte of data following the opcode contains a displacement to

be added to one of the IX or IY Index registers. The displacement is a two’s-complement

value in the range +127 to –128.

Figure 8

displays the indexed addressing.

Extended Addressing
The memory operand address is specified by two or three bytes following the opcode.

Fig-

ure 9

displays the extended addressing.

Relative Addressing
Relative addressing uses one byte of data following the opcode to specify a displacement

from the existing program to which a program jump can occur. The displacement is a

two’s-complement number that is added to the address of the opcode following the

Figure 8. Indexed Addressing

Figure 9. Extended Addressing

Operand

Op Code 2

Displacement (d)

Op Code 1

Index Register (IX or IY)

Memory Space

+

Operand

mm

MM

nn

Op Code

{MM, mm, nn}

Memory Space

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