Improving Networks Worldwide. UNH InterOperability Lab SATA Chapters 11 and 12 Device Command Layer Protocols

2 SATA Device Command Layer Protocols Presentation Topics Device Command Layer Protocol – Power-on and COMRESET – Device Idle – EXECUTE DEVICE DIAGNOSITC – DEVICE RESET – DMA data-in – FPDMA QUEUED (Host and Device) Other Command Layer Protocols

3 SATA Device Command Layer Protocols Command Layer Protocols Series of inter-related state machines Guidelines for devices and hosts on steps to take when processing and incoming or outgoing command

4 SATA Device Command Layer Protocols Presentation Topics Device Command Layer Protocol – Power-on and COMRESET – Device Idle – EXECUTE DEVICE DIAGNOSITC – DEVICE RESET – DMA data-in – FPDMA QUEUED (Host and Device) Other Command Layer Protocols

5 SATA Device Command Layer Protocols Power-on and COMRESET On reception of COMRESET from a Host, devices shall execute the hardware reset protocol regardless of current device command layer state or power management state Covers the basic power on procedures to be used by both Packet and Non- packet devices

6 SATA Device Command Layer Protocols Power-on and COMRESET DHR0: Hardware_reset_asserted – Command Layer has received a message from the Transport Layer that a COMRESET has been asserted – Device stays in this state until message from Phy State Machine is received saying that the hardware reset has been negated – Only transitions to DHR1

7 SATA Device Command Layer Protocols Power-on and COMRESET DHR1: Execute_diagnostics – During this state, a Device initializes its hardware and executes its power up diagnostic routines – Upon completion of power up diagnostic routines a Device can transition to DHR2 or DHR3

8 SATA Device Command Layer Protocols Power-on and COMRESET DHR2: Send_good_status – In this state, a Devices transmits a Register FIS to the Host indicating that the power up diagnostics have been completed successfully – The Device then transitions to DI0: Device_idle

9 SATA Device Command Layer Protocols Power-on and COMRESET DHR3: Send_bad_status – In this state, a Devices transmits a Register FIS to the Host indicating that the power up diagnostics have NOT been completed successfully – The Device then transitions to DI0: Device_idle

10 SATA Device Command Layer Protocols Presentation Topics Device Command Layer Protocol – Power-on and COMRESET – Device Idle – EXECUTE DEVICE DIAGNOSITC – DEVICE RESET – DMA data-in – FPDMA QUEUED (Host and Device) Other Command Layer Protocols

11 SATA Device Command Layer Protocols Device Idle Protocol The default state for all SATA Devices – Awaiting the reception of a FIS from the Host – State machine defines how to process commands and how to decide which command specific state machine to enter based on the received FIS

12 SATA Device Command Layer Protocols Device Idle Protocol DI0: Device Idle – Default State – Just waiting for something to happen from the Host – Numerous possible transitions from this state based on Host actions

13 SATA Device Command Layer Protocols Device Idle Protocol DI1: Check_FIS – Entered from DI0 upon reception of a FIS – Check C-bit and SRST-Bit of the FIS If C-bit asserted → DI2: Check_command If SRST-bit asserted → DSR0: Software_reset_asserted – Any other FIS → DI0: Device_idle

14 SATA Device Command Layer Protocols Device Idle Protocol DI2: Check_command – Check the fields of the command – 15 possible transitions out of this state based on the command type found when checking fields

15 SATA Device Command Layer Protocols Device Idle Protocol DI3: No_Command – Entered when a Device receives a command not supported – ABRT-bit of command set to one → DI0: Device_idle DI4: Set_service – Entered when Device is ready to complete data transfer for a queued command – SERV-bit of command set to one → DI0: Device_idle

16 SATA Device Command Layer Protocols Device Idle Protocol DI5: Service_test – Entered when a SERVICE Command is received – Check the command to see if a Register FIS needs to be transmitted for DRQ bit and to set the Tag – If PACKET PIO In/Out → DI7: Service_decode – Else → DI6: Service_send_tag

17 SATA Device Command Layer Protocols Device Idle Protocol DI6: Service_send_tag – Entered when a SERVICE command has been received – Device waits for a Register FIS with the BSY-bit de-asserted, DRQ-bit asserted, and an appropriate tag – Upon reception of the FIS → DI7: Service_decode

18 SATA Device Command Layer Protocols Device Idle Protocol DI7: Service_Decode – Check the command that has been received after the required Register FIS has been received – 6 Possible transitions based on the command type

19 SATA Device Command Layer Protocols Presentation Topics Device Command Layer Protocol – Power-on and COMRESET – Device Idle – EXECUTE DEVICE DIAGNOSITC – DEVICE RESET – DMA data-in – FPDMA QUEUED (Host and Device) Other Command Layer Protocols

20 SATA Device Command Layer Protocols Execute Device Diagnostics Protocol Command Class for the EXECUTE DEVICE DIAGNOSTIC command – If COMRESET or a FIS with SRST-bit asserted is received, the Device shall execute the COMRESET Command Protocol or the Software Reset Command Protocol respectively Describes the process for EXECUTE DEVICE DIAGNOSTIC command

21 SATA Device Command Layer Protocols Execute Device Diagnostics Protocol DEDD0: Execute_device_diag – In this state, a Device will execute its internal diagnostic procedures If diagnostics completed successfully → DEDD1: Send_good_status Else → DEDD2: Send_bad_status From DEDD1 and DEDD2 → DI0: Device_Idle

22 SATA Device Command Layer Protocols Presentation Topics Device Command Layer Protocol – Power-on and COMRESET – Device Idle – EXECUTE DEVICE DIAGNOSITC – DEVICE RESET – DMA data-in – FPDMA QUEUED (Host and Device) Other Command Layer Protocols

23 SATA Device Command Layer Protocols Device Reset Protocol Command Class for the DEVICE RESET command – If COMRESET or a FIS with SRST-bit asserted is received, the Device shall execute the COMRESET Command Protocol or the Software Reset Command Protocol respectively When this command is received, a Device will stop all activity

24 SATA Device Command Layer Protocols Device Reset Protocol DDR0: Device_reset – Upon reception of this command, a Device will halt all execution of any outstanding commands and will hald all background activity – When activity has ceased → DDR1: Send_good_status DDR1: Send_good_status – Device requests the Host transmit a Register FIS – Upon reception of this FIS → DI0: Device_Idle

25 SATA Device Command Layer Protocols Presentation Topics Device Command Layer Protocol – Power-on and COMRESET – Device Idle – EXECUTE DEVICE DIAGNOSITC – DEVICE RESET – DMA data-in – FPDMA QUEUED (Host and Device) Other Command Layer Protocols

26 SATA Device Command Layer Protocols DMA Data-in Protocol Command Class for the READ DMA and READ DMA EXT commands Execution of this command induces the transfer of one ore more blocks of data from the device to the host use using a DMA transfer Command Protocol for most read operations in modern, non-packet devices

27 SATA Device Command Layer Protocols DMA Data-in Protocol DDMAI0: DMA_in – In this state, a Device will prepare the date for transfer to the host – When Data FIS is ready → DDMAI1: Send_data – Otherwise, command has been completed or aborted → DDMA2: Send_status

28 SATA Device Command Layer Protocols DMA Data-in Protocol DDMAI1: Send_data – In this state, the Device shall transmit the prepared FIS to the host DDMAI2: Send_status – A Device enters this state when all the data for a command has been transmitted to a Host or an error has caused the command to abort

29 SATA Device Command Layer Protocols Presentation Topics Device Command Layer Protocol – Power-on and COMRESET – Device Idle – EXECUTE DEVICE DIAGNOSITC – DEVICE RESET – DMA data-in – FPDMA QUEUED (Host and Device) Other Command Layer Protocols

30 SATA Device Command Layer Protocols FPDMA Queued Protocol Command Class for READ FPDMA QUEUED and WRITE FPDMA QUEUED commands – Special Read and Write commands for Native Command Queuing features found in SATA2+

31 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ1: AddCommandToQueue – Upon determining a FPDMA command has been received, a Device will add the command to its internal queue and store the command's TAG value – Successful en-queuing → DFPDMAQ2: CleareInterfaceBsy – Else → DFPDMAQ12: BrokenHost_ClearBusy

32 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ2: ClearInterfaceBsy – Transmit a Register FIS to the host with BSY and DRQ bits deasserted, indicating the Device is ready to receive the next command – Upon transmission → DI0: Device_idle

33 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ3: DataPhaseReadSetup – State entered when the device is ready to transmit data from a previously queued READ FPDMA QUEUED command – In this state, a Device will attempt to setup up a host memory write DMA connection with the Host – Once the connection is established, a Device will transition to DFPDMAQ8

34 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ4: DataPhasePreWriteSetup – State entered when the device is ready to receive data from a previously queued WRITE FPDMA QUEUED command – In this state a Device needs to determine if Auto-Activate is supported an enabled If yes, → DFPDMAQ5: DataPhase_WriteSetup Else → DFPDMAQ6: DatePahse_OldWriteSetup

35 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ5: DataPhase_WriteSetup – This state is entered when a Device is ready to Auto-Activate – A device transmits a DMA Setup FIS to the host with a DMA buffer Id, the queued TAG value, the direction bit cleared (Host Memory Read), and the AA bit set to one – Once Setup FIS is completed → DFPDMAQ9: DataXmitWrite

36 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ6: DataPhase_OldWriteSetup – This state is entered when Auto-Activate is not supported or enabled – A device transmits a DMA Setup FIS to the host with a DMA buffer Id, the queued TAG value, the direction bit cleared (Host Memory Read), and the AA bit set to zero – Once Setup FIS is completed → DFPDMAQ9: DataXmitWrite

37 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ7: DataPhaseXmit_Activate – This state is entered after a device completed setup for a WRITE DPDMA QUEUED command – While in this state a Device transmits a DMA Activate FIS indicating its readiness to receive DATA FISes – The device then transitions to DFPDMAQ9: DataXmitWrite

38 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ8: DataXmitRead – This state is entered after a device has completed setup for a READ FPDMA QUEUED command – A device continues to transmit Data FISs until the command has been completed or an error has been encountered – Device transitions to DI0: Device_idle upon completion

39 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ9: DataXmitWrite – This state is entered after a device has completed setup for a WRITE FPDMA QUEUED command – A device continues to receive DATA FISes until the command has been completed or an error has been encountered – Device transitions to DI0: Device_idle upon completetion

40 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ10: SendStatus – This state is entered after a device has completed the data transfer associated with a command – In this state, a device will transmit a Set Device Bits FIS to the host indicating the completion of the command – Following the transmission of this FIS, a device will transition to DI0: Device_idle

41 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ11: Error – This state is entered when a device has encountered an unrecoverable error – When this state is entered, a device halts all transmissions and transmits a Set Device Bits FIS to the host indictating the error condition – A device then transitions to DFPDMAQ13: WaitforClear

42 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ12: BrokenHost_ClearBusy – This state is entered when a device receives a READ or WRITE FPDMA QUEUED command with a tag that exists already in the queue or a non-queued command is received while there are still outstanding commands in the queue – Upon entering this state, a device will transmit a Register FIS to the host indicating the error condition and then transition to DFPDMAQ13

43 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ13: WaitforClear – This state is entered when a device has transmitted an error FIS and is waiting for a READ LOG EXT command or a Soft-Reset – All other commands will be responded to with an Error FIS – When the READ LOG EXT command is received the device shall transition to DFPDMAQ12

44 SATA Device Command Layer Protocols FPDMA Queued Protocol DFPDMAQ14: SendQueue_CleanACK – This stae is entered when the Host has responseded to an error FIS with a READ LOG EXT command – The Device will discard all queued commands remaining and transmit a Set Device Bits FIS with the ERR bit cleared, Error Field cleared, and Sactive = FFFFFFFFh and interup cleared – Upon transmission of this FIS, the device shall transition to DPIOI0:PIO_in

45 SATA Device Command Layer Protocols FPDMA Queued Protocol (Hosts) This state machine describes the behavior for Native Command Queuing Hosts This class is largely similar to the behavior of the devices but also covers: – TAG assignment – Error Recovery – Retrying Failed Commands

46 SATA Device Command Layer Protocols Presentation Topics Device Command Layer Protocol – Power-on and COMRESET – Device Idle – EXECUTE DEVICE DIAGNOSITC – DEVICE RESET – DMA data-in – FPDMA QUEUED (Host and Device) Other Command Layer Protocols

47 SATA Device Command Layer Protocols Software Reset Protocol This state machine covers how a device handles receiving a FIS with the SRST bit asserted Essentially the same as the DEVICE RESET Command Protocol

48 SATA Device Command Layer Protocols Non-Data Protocol This state machine describes how a device will handle receiving a non-data command FIS Commands include: FLUSH CACHE, IDLE, MEDIA LOCK, SEEK, NOP, and SET MULTIPLE MODE among others

49 SATA Device Command Layer Protocols PIO Data-in and Data-out Protocol These two state machines describe how commands will responds to PIO requests (Diagnostic and legacy commands from previous ATA standards) Commands include IDENTIFY DEVICE, READ SECTORS, SMART READ DATA, DOWNLOAD MICROCODE, and WRITE SECTORS among others

50 SATA Device Command Layer Protocols Packet Protocol This state machine describes how a device will handle receiving a packet based commands. Packet commands are used by Optical Disc Drives and other ATAPI device which do not utilize the traditional PIO and DMA interfaces defined with ATA