CHAPTER 3 CPU INSTRUCTION SET SUMMARY
85
Table 3-3. Load/store Instruction (Extended ISA)
Instruction
Format and Description
Load Doubleword
LD rt, offset (base)
The offset is sign extended and then added to the contents of the register base to form the virtual address.
The doubleword of the memory location specified by the address are loaded into register rt.
Load Doubleword Left
LDL rt, offset (base)
The offset is sign extended and then added to the contents of the register base to form the virtual address.
Shifts to the left the double word whose address is specified so that the address-specified byte is at the
left-most position of the double word. The result of the shift operation is merged with the contents of
register rt and loaded to register rt.
Load Doubleword
Right
LDR rt, offset (base)
The offset is sign extended and then added to the contents of the register base to form the virtual address.
Shifts to the right the double word whose address is specified so that the address-specified byte is at
the right-most position of the double word. The result of the shift operation is merged with the contents
of register rt and loaded to register rt.
Load Word Unsigned
LWU rt, offset (base)
The offset is sign extended and then added to the contents of the register base to form the virtual address.
The word of the memory location specified by the address are zero extended and loaded into register rt
Store Doubleword
SD rt, offset (base)
The offset is sign extended and then added to the contents of the register base to form the virtual address.
The contents of register rt are stored to the memory location specified by the address.
Store Doubleword Left
SDL rt, offset (base)
The offset is sign extended and then added to the contents of the register base to form the virtual address.
Shifts to the right the contents of register rt so that the left-most byte of the double word is in the
position of the address-specified byte. The result is stored to the lower doubleword in memory.
Store Doubleword
Right
SDR rt, offset (base)
The offset is sign extended and then added to the contents of the register base to form the virtual address.
Shifts to the left the contents of register rt so that the right-most byte of the double word is in the
position of the address-specified byte. The result is stored to the upper doubleword in memory.
op
base
rt
offset