APPENDIX A MIPS III INSTRUCTION SET DETAILS
504 Preliminary Users Manual S15543EJ1V0UM
LD Load Doubleword LD
base

LD

1 1 0 1 1 1 rt offset

31 26 25 21 20 16 15 0
655 16
Format:
LD rt, offset (base)
Description:
The 16-bit
offset
is sign-extended and added to the contents of general register
base
to form a virtual address.
The contents of the 64-bit doubleword at the memory location specified by the effective address are loaded into
general register
rt
.
If any of the three least-significant bits of the effective address are non-zero, an address error exception occurs.
This operation is defined in 64-bit mode or in 32-bit kernel mode. Execution of this instruction in 32-bit user or
supervisor mode causes a reserved instruction exception.
Operation:
64 T: vAddr
((
offset15)48 || offset15..0) + GPR [base]
(
pAddr
,
uncached
)
AddressTranslation
(
vAddr
,
DATA
)
data LoadMemory (uncached, DOUBLEWORD, pAddr, vAddr, DATA)
GPR
[
rt
]
data
Exceptions:
TLB refill exception
TLB invalid exception
Bus error exception
Address error exception
Reserved instruction exception (32-bit user mode/supervisor mode)