Ultrastar C10K600 OEM Specification

• Pathway Blocked Count: this field indicates the number of times the port has retried this connection request due to receiving OPEN_REJECT (PATHWAY BLOCKED). The Drive willl not increment the PATHWAY BLOCKED

COUNT value past FFh.

• Arbitration Wait Time: this field indicates how long the port transmitting the OPEN address frame has been waiting for a connection request to be accepted. For values from 0000h to 7FFFh, the Arbitration Wait Time timer increments in one microsecond steps. For values from 8000h to FFFFh, the Arbitration Wait Time timer increments in one millisecond step.

•

More Compatible Features: this field is set to zero and ignored by the Drive per SAS 1.1.

17.6.2 Link Layer Error Handling

This section defines the Link layer error handling of the drive.

Error

IDENTIFY Timeout

BREAK Received

Error Handling Procedure

If IDENTIFY is not received before the IDENTIFY timer expires (1ms), firmware is notified and the drive transmits a COMINIT to initiate a new link reset.

If BREAK is received while the drive has ACK/NAK balance, BREAK or

BREAK_REPLY is transmitted and a new connection may be opened if the drive still has frames to transmit. Firmware is not notified. If BREAK is received while the drive does NOT have ACK/NAK balance, BREAK or

BREAK_REPLY is transmitted and the current command is aborted and will return Check Condition status with sense data indicating an ACK/NAK timeout.

NAK and ACK/NAK Timeout If a NAK is received on a RESPONSE frame, the RESPONSE frame is retransmitted with the RETRANSMIT bit set to zero. If an ACK or NAK is not received for a RESPONSE frame within 1ms, the RESPONSE frame will be retransmitted with the RETRANSMIT bit set to one. The drive will retry sending a RESPONSE frame once.

Bad Frame CRC

If a frame fails the CRC check, the frame is NAKed by the drive and discarded.

This is a link layer function. The command associated with a NAKed DATA or

XFER_RDY frame is aborted with check condition status and sense data corresponding to DATA_PHASE_ERROR is returned. COMMAND frames that fail the CRC check are NAKed and discarded.

OPEN_REJECT

OPEN_REJECT – Retryable Variations

• OPEN_REJECT(RETRY) - Will be retried indefinitely by the drive. This case is considered to be occur when the initiator is temporarily not available to accept connections (for example when it is not able to extend R-Rdy credit at this time due to lack of buffers...), so the initiator will ask us to keep "RETRY"-ing, until it becomes available at a later time. Thus, we don't consider this an error condition, but part of normal behavior for the initiator.

• OPEN_REJECT(RATE_NOT_SUPPORTED) – If this occurs, it must mean that a link between the drive and initiator renegotiated to a lower link rate after the command was received. In this case, we retry in a new connection at 1.5Gbps. If this error is received for a 1.5Gbps connection, the command is internally aborted.

OPEN_REJECT – (PATHWAY_BLOCKED)

• OPEN_REJECT(BAD_DESTINATION),

OPEN_REJECT(WRONG_DESTINATION),

OPEN_REJECT(PROTOCOL_NOT_SUPPORTED) – If these

OPEN_REJECTs are received, we internally abort the command.

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Credit Timeout

DONE Timeout

CREDIT_BLOCKED

OPEN Frame Checking

OPEN Response Timeout

CLOSE Timeout

Phy Not Ready

If credit is not received before the credit timer expires,

DONE(CREDIT_TIMEOUT) is sent to the Initiator.

If credit is extended and the DONE timer expires, BREAK is sent by hardware to tear down the connection.

If CREDIT BLOCKED is received and the drive has frames to send in the current connection, DONE(CREDIT_TIMEOUT) is returned. Otherwise,

DONE(NORMAL) is returned.

Reserved fields in the OPEN frame are not checked.

• The Dest Address field is checked, and if it doesn’t match

OPEN_REJECT(WRONG_DESTINATION) is returned.

• The Protocol field is checked and if it isn’t set to SSP

OPEN_REJECT(PROTOCOL_NOT_SUPPORTED) is returned.

• If the Link Rate exceeds the physical link rate on that port,

OPEN_REJECT(LINK_RATE_NOT_SUPPORTED) is returned.

• The Initiator bit is not checked.

If AIP or OPEN_ACCEPT is not received before the OPEN Response timer expires, the hardware transmits BREAK.

If CLOSE is not received before the CLOSE timer expires, the hardware transmits BREAK.

If Link Reset occurs outside of a connection, commands can execute normally across the link reset. If a link reset occurs inside of a connection, the behavior is similar to BREAK in that it is treated as an abruptly closed connection. In cases where the command cannot be continued normally (e.g. a frame is corrupted by

OOB signals, or we do not have ACK/NAK balance), the command is terminated with CHECK CONDITION status with sense data corresponding to ACK/

NAK TIMEOUT.

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