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Chapter 17. H8/300 Dependent Features

@rn+

Register indirect with post increment

@ rn

Register indirect with pre decrement

@aa

@aa:8

@aa:16

@aa:24

Absolute address

aa

. (The address size

:24

only makes sense on the H8/300H.)

#xx

#xx:8

#xx:16

#xx:32

Immediate data

xx

. You may specify the

:8

,

:16

, or

:32

for clarity, if you wish; but

as

neither

requires this nor uses it  the data size required is taken from context.

@@aa

@@aa:8

Memory indirect. You may specify the

:8

for clarity, if you wish; but

as

neither requires this nor

uses it.

17.3. Floating Point

The H8/300 family has no hardware floating point, but the

.float

directive generates ieee floating 

point numbers for compatibility with other development tools.

17.4. H8/300 Machine Directives

as

has the following machine dependent directives for the H8/300:

.h8300h

Recognize and emit additional instructions for the H8/300H variant, and also make

.int

emit

32 bit numbers rather than the usual (16 bit) for the H8/300 family.

.h8300s

Recognize and emit additional instructions for the H8S variant, and also make

.int

emit 32 bit

numbers rather than the usual (16 bit) for the H8/300 family.

.h8300hn

Recognize and emit additional instructions for the H8/300H variant in normal mode, and also

make

.int

emit 32 bit numbers rather than the usual (16 bit) for the H8/300 family.