MIPS R10000 Microprocessor User's Manual - SGI TechPubs Library

262 Chapter 14.
Errata
BPState: this field contains the new 2-bit state for a conditional branch after it is
verified. It is also used to hold the 2-bit state to read/write when a branch
prediction table read/write operation is executed.
BPIdx: this field contains the index to the Branch Prediction Table (BPT) for BPT
read/write/initialization operations, and should contain VA[11:3] of the branch
for BPT read/write operations. The upper six bits of the BPIdx field contain the
line address for BPT line initialization operations; the lower three bits of BPIdx are
ignored.
BPOp: this field indicates the following BPT operations:
002: BPT read
01 2 : BPT write
10 2 : initializes BPT line to all zeroes (strongly not taken)
11 2 : initializes BPT line to all ones (strongly taken).
0: Reserved. Must be written as zeroes, and returns zeroes when read.
Figure 14-21 shows the format of the Diagnostic register.
63
31 28 27 23 22 21 20 19
BS
BS
Idx
Idx
0
0
DBRC
BRC
BRC
V W
V W H
4 5 1
1 1 1
Figure 14-21 Diagnostic Register Format
Version 2.0 of January 29, 1997 MIPS R10000 Microprocessor User's Manual
52
51
0 ITLBM
0
12 4
16
18
MP
MP
1
48
17
47
16 15
14 13 12 11
BP
Mode
Mode
State
State
0
0 Idx
Idx
0
0
Op
Op
2 2 2 9 1 2
3
2
1
32
0