Datasheet

Datasheet 06/04/2012
PSFEM2XXXGXXXX Viking Technology
Revision A2 Page 38 of 46
www.vikingtechnology.com
ID Attribute Name Description Rational
195 ECC On-the-Fly
Error Count
This attribute tracks the number of
uncorrectable ECC errors (UECC). The
normalized value is only computed
when the number of bits in the
"BitsRead" count is in the range of
10^10 to 10^12. The count is cleared at
power on reset and when >10^12 bits
have been read.
Normalized Equation:
10log10(BitsRead/ECCOnTheFlyErrors
+ 1)
SectorsRead= Number of sectors read
SectorsToBits= 512*8
BitsRead= SectorsRead*SectorsToBits
Normalized Value Range:
Best = 120
Worst = 38
Invalid = 0
Raw Usage:
[3-0] : Number of sectors read
[6-4]: ECCOnTheFlyErrors (UECC)
count
The ECC On The Fly error rate
includes all uncorrectable ECC
errors (UECC) tracked by the
controller. The normalized
equation for ECC On The Fly
error rate is logarithmic since the
valid BER range of the attribute
spans from 1.00E-10 to 1.00E-
12. To force positive numbers,
the numerator and denominator
are flipped. One is then added to
the number of errors in the
denominator to avoid a divide-
by-0 condition if no errors are
encountered. By taking the log of
the inverted BER and multiplying
by ten a reasonable range of
normalized values from 120 to
38 (representing a BER range of
1.00E-13 to 1.68E-04 ) are
presented. As defined, this
Attribute is identical to Attribute
201 and Attribute 204.
This Attribute reads ‘0’ until a
sample size between 10E10 and
10E12 is available to be tracked
by this Attribute.
Note that many UECC errors
counted by this Attribute are
corrected by RAISE correction.