Device Power Connector Pin 11 Definition; Phy Event Counters - Hitachi HDS723020BLA642 Specifications

9.17 SATA II Optional Features
There are several optional features defined in SATA II. The following shows whether these features are
supported or not.
9.17.1 Asynchronous Signal Recovery
The device supports asynchronous signal recovery defined in SATA II.
9.17.2

Device Power Connector Pin 11 Definition

SATA II specification defines that Pin 11 of the power segment of the device connector may be used to
provide the host with an activity indication and disabling of staggered spin-up.
9.17.3

Phy Event Counters

Phy Event Counters are an optional feature to obtain more information about Phy level events that occur on the
interface. This information may aid designers and integrators in testing and evaluating the quality of the interface.
A device indicates whether it supports the Phy event counters feature in IDENTIFY (PACKET) DEVICE Word 76,
bit 10. The host determines the current values of Phy event counters by issuing the READ LOG EXT command
with a log page of 11h. The counter values shall not be retained across power cycles. The counter values shall
be preserved across COMRESET and software resets.
The counters defined can be grouped into three basic categories: those that count events that occur during Data
FIS transfers, those that count events that occur during non-Data FIS transfers, and events that are unrelated to
FIS transfers. Counters related to events that occur during FIS transfers may count events related to
host-to-device FIS transfers, device-to-host FIS transfers, or bi-directional FIS transfers. A counter that records
bi-directional events is not required to be the sum of the counters that record the same events that occur on
device-to-host FIS transfers and host-to-device FIS transfers.
Implementations that support Phy event counters shall implement all mandatory counters, and may support any
of the optional counters as shown in 0. Note that some counters may increment differently based on the speed
at which non-Data FIS retries are performed by the host and device. Implementations may record CRC and
non-CRC error events differently. For example, there is a strong likelihood that a disparity error may cause a
CRC error. Thus, the disparity error may cause both the event counter that records non-CRC events and the
event counter that records CRC events to be incremented for the same event. Another example implementation
difference is how a missing EOF event is recorded; a missing EOF primitive may imply a bad CRC even though
the CRC on the FIS may be correct. These examples illustrate that some Phy event counters are sensitive to the
implementation of the counters themselves, and thus these implementation sensitive counters cannot be used
as an absolute measure of interface quality between different implementations.
9.17.3.1
Counter Reset Mechanisms
There are two mechanisms by which the host can explicitly cause the Phy counters to be reset.
The first mechanism is to issue a BIST Activate FIS to the device. Upon reception of a BIST Activate FIS the
device shall reset all Phy event counters to their reset value. The second mechanism uses the READ LOG EXT
command. When the device receives a READ LOG EXT command for log page 11h and bit 0 in the Features
register is set to one, the device shall return the current counter values for the command and then reset all Phy
event counter values.
9.17.3.2
Counter Identifiers
Each counter begins with a 16-bit identifier. 0 defines the counter value for each identifier. Any unused counter
slots in the log page should have a counter identifier value of 0h.
Optional counters that are not implemented shall not be returned in log page 11h. A value of „0‟ returned for a
counter means that there have been no instances of that particular event. There is no required ordering for event
counters within the log page; the order is arbitrary and selected by the device vendor.
Hitachi hard disk drive specifications
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