Addressing Modes; Assembler Directives For The Z8000 - Red Hat ENTERPRISE LINUX 4 - USING AS Using Manual

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39.2.3. Addressing Modes

as understands the following addressing modes for the Z8000:
rl
n
rh
n
r
n
rr
n
rq
n
Register direct: 8bit, 16bit, 32bit, and 64bit registers.
@r
n
@rr
n
Indirect register: @rr
addr
Direct: the 16 bit or 24 bit address (depending on whether the assembler is in segmented or
unsegmented mode) of the operand is in the instruction.
address(r )
n
Indexed: the 16 or 24 bit address is added to the 16 bit register to produce the final address in
memory of the operand.
r (# )
n imm
rr (# )
n imm
Base Address: the 16 or 24 bit register is added to the 16 bit sign extended immediate displace-
ment to produce the final address in memory of the operand.
r (r )
n m
rr (r )
n m
Base Index: the 16 or 24 bit register r
r to produce the final address in memory of the operand.
m
#
xx
Immediate data

39.3. Assembler Directives for the Z8000

The Z8000 port of as includes additional assembler directives, for compatibility with other Z8000
assemblers. These do not begin with
segm
.z8001
Generate code for the segmented Z8001.
unsegm
in segmented mode, @r
n
.
xx
(unlike the ordinary as directives).
.
Chapter 39. Z8000 Dependent Features
in unsegmented mode.
n
or rr is added to the sign extended 16 bit index register
n n