Using as: H8/300-Addressing

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9.12.2.3 Addressing Modes

as understands the following addressing modes for the H8/300:

rn

Register direct

@rn

Register indirect

@(d, rn)

@(d:16, rn)

@(d:24, rn)

Register indirect: 16-bit or 24-bit displacement d from register n. (24-bit displacements are only meaningful on the H8/300H.)

@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.