9.14.2.3 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.