UNH InterOperability Lab
Serial Attached SCSI (SAS)
Clause 7
Improving Networks Worldwide.
Improving Networks Worldwide.
SAS Clause 7
Presentation Topics
• Primitive Overview
• Primitive Types and definitions
• Open Connection Handshake
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SAS Clause 7
Primitives Overview
• Primitives are Dwords whose first
character isK28.5
• Example Primitive:
K28.5 D01.3 D01.3 D01.3
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SAS Clause 7
Primitive Format
• 1st character: K28.5
• 2nd character: Constant data character
• 3rd character: Constant data character
• Last character: Constant data character
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SAS Clause 7
Presentation Topics
• Primitive Overview
• Primitive Types and definitions
• Open Connection Handshake
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SAS Clause 7
Primitive Types
• ALIGN
• SOAF
• MUX
• EOAF
• NOTIFY
• ERROR
• AIP
• OPEN_ACCEPT
• BREAK
• OPEN_REJECT
• BROADCAST
• ACK
• CLOSE
• NAK
• HARD_RESET
• DONE
• TRAIN
• RRDY
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SAS Clause 7
ALIGN
• ALIGNs are used for:
– OOB signals (OOB signals are typically built with ALIGN)
– character and dword alignment during the speed
negotiation sequence
– physical link rate tolerance management after the phy reset
sequence and rate matching during connections
– ALIGN is used every 2048 dwords in SAS and 256 dwords
in SATA
ALIGN (0): K28.5 D10.2 D10.2 D27.3
ALIGN (1): K28.5 D07.0 D07.0 D07.0
ALIGN (2): K28.5 D01.3 D01.3 D01.3
ALIGN (3): K28.5 D27.3 D27.3 D27.3
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SAS Clause 7
MUX
• MUX is used if multiplexing is enabled as
follows:
– transmitted during the multiplexing
sequence substituted in place of an ALIGN being
– transmitted for physical link rate
tolerance
management or rate matching to confirm the
logical link number.
– MUX (LOGICAL LINK 0): K28.5 D02.0 D16.7
D31.4 MUX (LOGICAL LINK 1): K28.5 D04.7
D31.4 D27.4
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SAS Clause 7
NOTIFY
• NOTIFY may be substituted in place of any ALIGN being
transmitted for physical link rate tolerance management or rate
matching. It tells the device about power consumption
• A specific NOTIFY shall not be transmitted in more than three
consecutive dwords until at least three other dwords have been
transmitted.
• NOTIFY shall not be forwarded through expander devices.
• SAS target devices are not required to detect every transmitted
NOTIFY.
• NOTIFY (ENABLE SPINUP): K28.5 D31.3 D31.3 D31.3
• NOTIFY (POWER LOSS EXPECTED): K28.5 D31.3 D07.0 D01.3
• NOTIFY (RESERVED 1):K28.5 D31.3 D01.3 D07.0
• NOTIFY (RESERVED 2): K28.5 D31.3 D10.2 D10.2
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SAS Clause 7
AIP
• AIP is transmitted by an expander device
after a connection request to specify that the
connection request is being processed and
specify the status of the connection request.
• AIP means Arbitration In Process and is a
sequence primitive, it is sent 3 times
• AIP (NORMAL): K28.5 D27.4 D27.4 D27.4
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SAS Clause 7
BREAK
• BREAK is used to abort a connection request
or break a connection.
• BREAK_REPLY is used to confirm the receipt
of a BREAK
• It is a sequence primitive and sent 6 times
• BREAK: K28.5 D02.0 D24.0 D07.3
BREAK_REPLY: K28.5 D02.0 D29.7 D16.7
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SAS Clause 7
BROADCAST
• BROADCASTs are used to notify SAS ports
and expander devices in a SAS domain about
certain events.
• Is a sequence primitive and is sent 6 times
• BROADCAST (CHANGE): K28.5 D04.7 D02.0
D01.4
• BROADCAST (EXPANDER) K28.5 D04.7
D01.4 D24.0
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SAS Clause 7
CLOSE
• CLOSE is used to close a connection.
This primitive may be originated by a
SAS initiator port or a SAS target port.
• It is a sequence primitive and is sent 3
times
• CLOSE (NORMAL): K28.5 D02.0 D30.0
D27.4
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SAS Clause 7
EOAF
• EOAF specifies the end of an address
frame.
• EOAF K28.5 D24.0 D07.3 D31.4
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SAS Clause 7
ERROR
• ERROR should be transmitted by an
expander device while the expander
device is forwarding dwords from a
SAS physical link or SATA physical link
to a SAS physical link and receives an
invalid dword or an ERROR.
• ERROR: K28.5 D02.0 D01.4 D29.7
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SAS Clause 7
HARD_RESET
• HARD_RESET is used to force a phy to
generate a hard reset to its port.
• It comes before and IDENTIFY address frame
• It is a sequence primitive and is sent at least 6
times every time HARD_RESET is sent
• HARD_RESET 10bit characters: K28.5 D02.0
D02.0 D02.0
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SAS Clause 7
OPEN_ACCEPT
• OPEN_ACCEPT specifies the
acceptance of a connection request.
• OPEN_ACCEPT: K28.5 D16.7 D16.7
D16.7
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SAS Clause 7
OPEN_REJECT
• OPEN_REJECT specifies that a
connection request has been rejected
and specifies the reason for the
rejection.
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SAS Clause 7
OPEN_REJECT Types
• OPEN_REJECT (BAD DESTINATION)A connection request routes to a destination expander phy in the same
expander port as the source expander phy and the expander port is
using the direct routing method. 10bit:K28.5 D31.4 D31.4 D31.4
• OPEN_REJECT(CONNECTION RATE NOT SUPPORTED)The requested connection rate is not supported on some
physical link on the pathway between the source phy and
destination phy. When a SAS initiator phy is directly
attached to a SAS target phy, the requested connection rate
is not supported by the destination phy. 10bit:K28.5 D31.4 D04.7 D29.7
• OPEN_REJECT (WRONG DESTINATION)The destination SAS address does not match the SAS
address of the SAS port to which the connection request
was delivered. 10bit:K28.5 D31.4 D16.7 D24.0
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SAS Clause 7
SOAF
• SOAF specifies the start of an address
frame
• SOAF:K28.5 D24.0 D30.0 D01.4
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SAS Clause 7
TRAIN/ TRAIN_DONE
• Are used during Train-SNW during
speed negotiation.
• Are sequence primitives and are sent 6
times
• TRAIN:K28.5 D30.3 D30.3 D30.3
• TRAIN_DONE:K28.5 D30.3 D30.3 D10.2
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SAS Clause 7
ACK
• ACK specifies the positive
acknowledgement of an SSP frame.
• Used only in SSP and SMP connections
• ACK: K28.5 D01.4 D01.4 D01.4
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SAS Clause 7
DONE
• DONE is used to start closing an SSP
connection and specify a reason for
doing so.
• DONE is not used during an SMP or
STP connection
• DONE(Normal):K28.5 D30.0 D30.0 D30.0
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SAS Clause 7
EOF
• EOF specifies the end of an SSP or SMP
frame
• EOF:K28.5 D24.0 D16.7 D27.4
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SAS Clause 7
NAK
• NAK specifies the negative
acknowledgement of an SSP frame and
the reason for doing so.
• NAK (CRC ERROR) K28.5 D01.4 D27.4
D04.7
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SAS Clause 7
RRDY
• RRDY is used to increase SSP frame
credit
• Means Receive Ready
• Used to let another device know that it is
ready to receive data/commands
• RRDY(Normal) 10bit:K28.5 D01.4 D24.0 D16.7
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SAS Clause 7
SOF
• SOF specifies the start of an SSP or SMP
frame.
• SOF: K28.5 D24.0 D04.7 D07.3
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SAS Clause 7
Presentation Topics
• Primitive Overview
• Primitive Types and definitions
• Open Connection Handshake
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SAS Clause 7
OPEN Connection Handshake
1st: The SAS initiator sends a SOAF to
the Target with the address
information and closes the information
with a EOAF.
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SAS Clause 7
OPEN Connection Handshake
2nd: The Target then responds with an
OPEN_ACCEPT and RRDY frames.
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SAS Clause 7
OPEN Connection Handshake
• 3rd: The Initiator then sends a data
frame starting with a SOF frame
followed by dwords and closes the
frame with EOF.
• 4th: The Target responds with an ACK
or NAK and then transmits a RRDY,
when ready to receive.
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SAS Clause 7
OPEN Connection Handshake
• 5th: The Initiator transmits a DONE
primitive when it is finished
transmitting. The Target responds with
a DONE.
• 6th: Then the Initiator transmits CLOSE,
3 times to close the connection.
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SAS Clause 7
OPEN Connection Handshake
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