44
Software Environment
Chapter 3
AMD-K6-2E+ Embedded Processor Data Sheet
23542A/0—September 2000
Preliminary Information
3.2
Model-Specific Registers (MSR)
The AMD-K6-2E+ processor provides eleven Model-Specific
Registers (MSRs) in the standard-power versions and twelve
MSRs in the low-power versions.
s
The value in the ECX register selects the MSR to be
addressed by the RDMSR and WRMSR instructions.
s
The values in EAX and EDX are used as inputs and outputs
by the RDMSR and WRMSR instructions.
Table 5 lists the MSRs and the corresponding value of the ECX
register. Figures
30 through
43 starting on
page 45 show the
MSR formats.
For more information about the MSRs, see the Embedded
AMD-K6 Processors BIOS Design Guide Application Note, order#
23913.
Fo r mo re in fo rma tio n ab o ut the RD MSR and WRMSR
instructions, see the AMD K86 Family BIOS and Software Tools
Development Guide, order# 21062.
Table 5.
AMD-K6-2E+ Processor Model-Specific Registers
Model-Specific Register
Value of ECX
Machine Check Address Register (MCAR)
00h
Machine Check Type Register (MCTR)
01h
Test Register 12 (TR12)
0Eh
Time Stamp Counter (TSC)
10h
Extended Feature Enable Register (EFER)
C000_0080h
SYSCALL/SYSRET Target Address Register (STAR)
C000_0081h
Write Handling Control Register (WHCR)
C000_0082h
UC/WC Cacheability Control Register (UWCCR)
C000_0085h
Processor State Observability Register (PSOR)
C000_0087h
Page Flush/Invalidate Register (PFIR)
C000_0088h
Level-2 Cache Array Register (L2AAR)
C000_0089h
Enhanced Power Management Register (EPMR)1
Notes:
1. The EPMR register is supported in the low-power versions only of the AMD-K6-2E+ processor.
C000_0086h