Mips Technologies R4000 - Index Register (0)

MIPS R4000 Microprocessor User's Manual 85
Memory Management
Index Register (0)
The Index register is a 32-bit, read/write register containing six bits to
index an entry in the TLB. The high-order bit of the register shows the
success or failure of a TLB Probe (TLBP) instruction.
The Index register also specifies the TLB entry affected by TLB Read
(TLBR) or TLB Write Index (TLBWI) instructions.
Figure 4-11 shows the format of the Index register; Table 4-7 describes the
Index register fields.
Figure 4-11 Index Register
Table 4-7 Index Register Field Descriptions
Field Description
P
Probe failure. Set to 1 when the previous TLBProbe
(TLBP) instruction was unsuccessful.
Index
Index to the TLB entry affected by the TLBRead and
TLBWrite instructions
0
Reserved. Must be written as zeroes, and returns zeroes
when read.
Index Register
31
1
30 6 5 0
25 6
Index
P
0