NEC Network Controller uPD98502 - Manual (Page 538)

APPENDIX A MIPS III INSTRUCTION SET DETAILS
538 Preliminary User’s Manual S15543EJ1V0UM
SB
Store Byte
SB
base
SB
1 0 1 0 0 0
rt offset
31 26 25 21 20 16 15 0
6 5 5 16
Format:
SB 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 least-significant byte of register rt is stored at the effective address.
Operation:
32 T: vAddr ← ((offset
15
)
16
|| offset
15...0
) + GPR [base]
(pAddr, uncached)
← AddressTranslation (vAddr, DATA)
pAddr ← pAddr
PSIZE - 1...3
|| (pAddr
2...0
xor (ReverseEndian
3
))
byte
← vAddr
2...0
xor BigEndianCPU 3
data ← GPR [rt]
63 – 8 * byte...0 || 0
8 * byte
StoreMemory (uncached, BYTE, data, pAddr, vAddr, DATA)
64 T: vAddr ← ((offset
15
) 48 || offset
15...0
) + GPR [base]
(pAddr, uncached) ← AddressTranslation (vAddr, DATA)
pAddr ← pAddr
PSIZE - 1...3
|| (pAddr
2...0
xor (ReverseEndian 3 ))
byte ← vAddr
2...0
xor BigEndianCPU
3
data ← GPR [rt]
63 – 8 * byte...0
|| 0
8 * byte
StoreMemory (uncached, BYTE, data, pAddr, vAddr, DATA)
Exceptions:
TLB refill exception
TLB invalid exception
TLB modification exception
Bus error exception
Address error exception