
APPENDIX A MIPS III INSTRUCTION SET DETAILS
504
Preliminary User’s 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 ←
offset
15
)
48
|| offset
15..0
) + GPR [base]
pAddr
uncached
← AddressTranslation
vAddr
DATA
data ← Lo
adMemory (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)
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