9.41.2.3 Addressing Modes

as understands the following addressing modes for the SH. R n in the following refers to any of the numbered registers, but not the control registers.

R n
Register direct
@R n
Register indirect
@-R n
Register indirect with pre-decrement
@R n +
Register indirect with post-increment
@( disp , R n )
Register indirect with displacement
@(R0, R n )
Register indexed
@( disp , GBR)
GBR offset
@(R0, GBR)
GBR indexed
addr
@( disp , PC)
PC relative address (for branch or for addressing memory). The as implementation allows you to use the simpler form addr anywhere a PC relative address is called for; the alternate form is supported for compatibility with other assemblers.
# imm
Immediate data