Encoding:

Format:

SDC1 ft, offset(base)

Purpose:

Store Doubleword from Floating Point

To store a doubleword from an FPR to memory.

Description:

 memory[GPR[base] + offset] = FPR[ft]

The 64-bit doubleword in FPR ft is stored in memory at the location specified by the aligned effective address. The

16-bit signed offset is added to the contents of GPR base to form the effective address.

Restrictions:

Pre-Release 6: An Address Error exception occurs if EffectiveAddress_2..0 != 0 (not doubleword-aligned).

Release 6 allows hardware to provide address misalignment support in lieu of requiring natural alignment.

Note: The pseudocode is not completely adapted for Release 6 misalignment support as the handling is implementation dependent.

Operation:

vAddr = sign_extend(offset) + GPR[base]
(pAddr, CCA) = AddressTranslation(vAddr, DATA, STORE)
datadoubleword = ValueFPR(ft, UNINTERPRETED_DOUBLEWORD)
StoreMemory(CCA, DOUBLEWORD, datadoubleword, pAddr, vAddr, DATA)
paddr = paddr xor ((BigEndianCPU xor ReverseEndian) || 02)
StoreMemory(CCA, WORD, datadoubleword31..0, pAddr, vAddr, DATA)
paddr = paddr xor 0b100
StoreMemory(CCA, WORD, datadoubleword63..32, pAddr, vAddr+4, DATA)

Exceptions:

Coprocessor Unusable, Reserved Instruction, TLB Refill, TLB Invalid, TLB Modified, Address Error, Watch