Fluid Dynamic Bearings (Fdb); Staggered Spinup And Activity Indication (Sata Power Pin 11); Staggered Spinup; Activity Indication - Western Digital Purple PR1000M Technical Reference Manual

PR1000M
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 10).
3.19

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.

3.20 Staggered Spinup and Activity Indication (SATA Power Pin 11)

Note: This feature is available for specific OEM configurations.
SATA device power connector pin 11 (see "Standard Factory Connectors" on
page 10) is defined as a means by the host to DISABLE staggered spinup and it may
also be used by the device to provide the host with an activity indication. According
to the SATA spec, "Staggered Spin-up Disable and Activity Signal shall not be enabled
at the same time."

3.20.1 Staggered Spinup

When multiple disks are installed in an enclosure, it is desirable to provide a simple
mechanism by which a subsystem controller can sequence hard drive initialization to
minimize the current load presented during power up. Staggered spinup provides
this mechanism by preventing the hard drives from spinning up until after successful
PHY initialization (i.e., after PHY enters DP7:DR_Ready state).
Staggered spinup is only applicable during initial power-up. If a drive is spun down
using ATA commands—as a result of having been placed in Standby or Sleep power
modes, for example—the drive shall spin up following the rules that govern spinup
from low power modes described in ATA/ATAPI-6 or later.

3.20.2 Activity Indication

The host controller through SATA power pin 11 may access storage device status and
activity. The signal provided by the device for activity indication is a low-voltage low-
current signal. It is not suitable for directly driving an LED. A buffer circuit external to
the device must be employed to drive the LED. The activity signal is based on an
open-collector or open-drain active low driver. The device shall tolerate the activity
signal being shorted to ground.
3.21

CacheFlow™

CacheFlow is WD's unique, multi-generation disk caching system. It incorporates read
cache with write cache.
WD designed CacheFlow to obtain maximum performance with today's most popular
operating systems and applications. CacheFlow increases performance over prior
caching algorithms by increasing the number of times that requested data is in the
cache. This reduces the number of host commands that require actual media access
thereby improving overall drive performance.
Typical applications perform a variety of access patterns, such as random, sequential,
and repetitive. CacheFlow is designed to dynamically adapt to the changes in access
patterns that occur during the course of application execution.
2679-800020-A03 RELEASED 5/8/17 (WD CONFIDENTIAL)
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RODUCT EATURES
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