AMD 3200 Revision History - Page 72

Initial, Value, Stamp, Counter, Include, Offset, Error

Page 72 highlights

Revision Guide for AMD Family 15h Models 00h-0Fh Processors 48063 Rev. 3.18 October 2012 708 Initial Value of Time Stamp Counter May Include an Offset Error Description During the interval of time between the northbridge observing the RESET# deassertion and the processor cores initializing internal copies of the time stamp counter (TSC), the TSC appears to increment at a rate that is twice the actual processor core software P0 frequency. This introduces an initial offset error in the reset value for each processor core. The actual value of the offset error is unpredictable. On the first case of any P-state change (either due to a P-state limit change or a software initiated P-state change), any halt instruction or C-state activity, the above initial offset error is removed. It is possible that the BIOS could observe the TSC to change to a smaller value (i.e., the TSC may appear to decrement once) if the latency of this operation is less than the above introduced error. If the software was to perform a write to the TSC before this event, the offset error is also removed. Potential Effect on System None expected under normal circumstances. Suggested Workaround Contact your AMD representative for information on a BIOS update. Fix Planned No fix planned 72 Product Errata

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708
Initial
Value
of
Time
Stamp
Counter
May
Include
an
Offset
Error
Description
During
the
interval
of
time
between
the
northbridge
observing
the
RESET
#
deassertion
and
the
processor
cores
initializing
internal
copies
of
the
time
stamp
counter
(
TSC
,
the
TSC
appears
to
increment
at
a
rate
that
is
twice
the
actual
processor
core
software
P
0
frequency
.
This
introduces
an
initial
offset
error
in
the
reset
value
for
each
processor
core
.
The
actual
value
of
the
offset
error
is
unpredictable
.
On
the
first
case
of
any
P-state
change
(
either
due
to
a
P-state
limit
change
or
a
software
initiated
P-state
change
,
any
halt
instruction
or
C-state
activity
,
the
above
initial
offset
error
is
removed
.
It
is
possible
that
the
BIOS
could
observe
the
TSC
to
change
to
a
smaller
value
(
i
.
e
.,
the
TSC
may
appear
to
decrement
once
if
the
latency
of
this
operation
is
less
than
the
above
introduced
error
.
If
the
software
was
to
perform
a
write
to
the
TSC
before
this
event
,
the
offset
error
is
also
removed
.
Potential
Effect
on
System
None
expected
under
normal
circumstances
.
Suggested
Workaround
Contact
your
AMD
representative
for
information
on
a
BIOS
update
.
Fix
Planned
No
fix
planned
Revision
Guide
for
AMD
Family
15
h
Models
00
h-
0
Fh
Processors
48063
Rev
. 3.18
October
2012
72
Product
Errata