as understands the following addressing modes for the H8/300:
Register indirect: 16-bit or 24-bit displacement d from register n. (24-bit displacements are only meaningful on the H8/300H.)
Register indirect with post-increment
Register indirect with pre-decrement
aa. (The address size ‘:24’ only makes sense on the H8/300H.)
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.
Memory indirect. You may specify the ‘:8’ for clarity, if you wish; but
as neither requires this nor uses it.