Intel 64 and IA-32 Architectures Software Developers Manual Volume 3B, System Programming Guide Part 2

Table Of Contents
Vol. 3 B-109
MODEL-SPECIFIC REGISTERS (MSRS)
31:0 From Linear IP.
Linear address of the target of the
last branch instruction.
63:32 Reserved.
1D8H 472 63:0 Unique From Linear IP.
Linear address of the target of the
last branch instruction (If IA-32e
mode is active).
1D9H 473 MSR_DEBUGCTLA 0, 1, 2,
3, 4, 6
Unique Debug Control. (R/W)
Controls how several debug
features are used. Bit definitions
are discussed in the referenced
section.
See Section 18.7.2,
“MSR_DEBUGCTLA MSR.
1DAH 474 MSR_LASTBRANCH
_TOS
0, 1, 2,
3, 4, 6
Unique Last Branch Record Stack TOS.
(R)
Contains an index (0-3 or 0-15)
that points to the top of the last
branch record stack (that is, that
points the index of the MSR
containing the most recent branch
record).
See Section 18.7.3, “LBR Stack for
Processors Based on Intel
NetBurst Microarchitecture”; and
addresses 1DBH-1DEH and 680H-
68FH.
Table B-6. MSRs in the Pentium 4 and Intel Xeon Processors (Contd.)
Register
Address
Register Name
Fields and Flags
Model
Avail-
ability
Shared/
Unique
1
Bit Description
Hex Dec