
APPENDIX A MIPS III INSTRUCTION SET DETAILS
Preliminary User’s Manual S15543EJ1V0UM
509
LDR
Load Doubleword Right (2/3)
LDR
The contents of general register
rt
are internally bypassed within the processor so that no NOP is needed between
an immediately preceding load instruction which specifies register
rt
and a following LDR (or LDL) instruction which
also specifies register
rt
.
No address error exceptions due to alignment are possible.
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)
pAddr ← p
Addr
PSIZE - 1..3
|| (pAddr
2..0
xor ReverseEndian
3
)
if BigEndianMem = 1 then
pAddr ← pAddr
PSIZE - 1..3
|| 0
3
endif
byte ← vAddr
2..0
xor BigEndianCPU
3
mem ← LoadMemory (uncached, DOUBLEWORD-byte, pAddr, vAddr, DATA)
GPR [rt] ← GPR [rt]63..64 – 8 * byte
|| mem
63..8 * byte
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