Load and store instructions use a special syntax:
instr rt, imm(rs)
The memory address used for the load or store is rs + imm. The immediate is sign-extended.
Load Instructions[edit]
Loads a byte and does not sign-extend the value.
Loads a halfword, or two bytes, and does not sign-extend the value. The halfword must be aligned (i.e., it must start at an even address).
Loads a word (four-bytes) from memory. The word must be aligned (i.e., the last two bits of the address must be zero).
Store Instructions[edit]
Stores the least significant (rightmost) byte of rt to memory.
Stores the least significant (rightmost) halfword of rt to memory.
Stores the contents of rt in memory.