WD RE3 XL333M
Product Features
2679-701179-A01
RELEASED 11/13/08 (WD CONFIDENTIAL)
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errors. The procedure ends when error recovery is achieved or when all possible retries have
been attempted.
Extended Read Retry Procedure – This retry procedure tries combinations of positive/negative
track offsets and data DAC manipulations to recover the data. This retry procedure applies
only to read data recovery. The Read/Write Retry procedure performs the actual retry
operation.
When an extended retry operation is successful, the controller continues with the command.
The controller clears any changes in track offset or data DAC settings before the command
continues.
3.14
Hot Plug Support
SATA supports hot plugging (also known as “hot swapping”), the ability to swap out a failed
hard drive without having to power down the system or reboot. This capability contributes to
both data availability and serviceability without any associated downtime, making it a critical
feature for extending SATA into enterprise applications.
The drive supports hot plugging only in systems where a SATA hard drive storage backplane
is used.
The Serial ATA revision 2.5 specification requires staggered pins for both the hard drive and
drive receptacles. Staggered pins mate the power signals in the appropriate sequences
required for powering up the hot plugged device. These pins are also specified to handle in
excess of the maximum allowed inrush current that occurs during drive insertion. SATA-
compliant devices thus need no further modification to be hot pluggable and provide the
necessary building blocks for a robust hot plug solution, which typically includes:
Device detection even with power downed receptacles (typical of server applications).
Pre-charging resistors to passively limit inrush current during drive insertion.
Hot plug controllers to actively limit inrush current during drive insertion.
3.15
Active LED Status
The drive supports external LED requirements. It provides an activity LED output which is ON
during command execution and OFF otherwise.
The drive strength of this open Drain Drive Active signal is that it can sink 12mA to 0.4V Max.
It is 5V tolerant, meaning that the external LED may be driven from +5V or +3.3V so long as
the Host system provides a series resistor to limit the LED current to the lower of 12mA or the
rated operating current of the LED. As an example with +5V and a 2 volt forward drop across
a 10mA LED, a 300 Ohm 5% 1/16W resistor would be suitable. In the case of a 3.3V supply
for the same LED, the resistor would be 130 Ohm 5% 1/16W.
The pin corresponding to P11 shall be used for Active LED (see “Device Plug Connector Pin
Definitions” on page 13).
3.16
Fluid Dynamic Bearings (FDB)
Bearing design that incorporates a layer of high-viscosity lubricant instead of ball bearings in
the hard drive spindle motor. As an alternative to conventional ball bearing technology, FDB
designs provide increased non-operational shock resistance, speed control, and improved
acoustics.
3.17
Staggered Spinup and Activity Indication (SATA Power Pin 11)
SATA device power connector pin 11 (see “Standard Factory Connectors” on page 13) is
defined as a means by the host to DISABLE staggered spinup and it may also be used by the
