Chapter 39.

Z8000 Dependent Features

The Z8000 as supports both members of the Z8000 family: the unsegmented Z8002, with 16 bit

addresses, and the segmented Z8001 with 24 bit addresses.

When the assembler is in unsegmented mode (specified with the

unsegm

directive), an address takes

up one word (16 bit) sized register. When the assembler is in segmented mode (specified with the

segm

directive), a 24 bit address takes up a long (32 bit) register. Section 39.3 Assembler Directives

for the Z8000, for a list of other Z8000 specific assembler directives.

39.1. Options

 z8001

Generate segmented code by default.

 z8002

Generate unsegmented code by default.

39.2. Syntax

39.2.1. Special Characters

!

is the line comment character.

You can use

;

instead of a newline to separate statements.

39.2.2. Register Names

The Z8000 has sixteen 16 bit registers, numbered 0 to 15. You can refer to different sized groups of

registers by register number, with the prefix

r

for 16 bit registers,

rr

for 32 bit registers and

rq

for

64 bit registers. You can also refer to the contents of the first eight (of the sixteen 16 bit registers) by

bytes. They are named

rln

and

rhn

.

byte registers

rl0 rh0 rl1 rh1 rl2 rh2 rl3 rh3

rl4 rh4 rl5 rh5 rl6 rh6 rl7 rh7

word registers

r0 r1 r2 r3 r4 r5 r6 r7 r8 r9 r10 r11 r12 r13 r14 r15

long word registers

rr0 rr2 rr4 rr6 rr8 rr10 rr12 rr14

quad word registers

rq0 rq4 rq8 rq12