Serial Ata Bus Application Technology
A serial Ata (SATA-Serial ATA) is the Ata-7 serial version of SATA 1.0 developed by the storage device developers represented by Intel. The objective is to make ATA-based storage a lot more widely made use of in desktop, mobile storage devices, low-end servers and network storage space locations  In April 2004, IDF once again improved the data transfer and physical layer adapter of Standard 1.0, and also provided the improved basic SATA I to be suitable with SAS physical layer as well as satisfy the storage space demands of data center  The efficiency of ATA-based storage device overlaps that of middle-and low-end business SCSI storage device, which appropriates for data life process and enterprise storage space layering. Representing the change of ATA physical user interface framework, SATA hard disk has some changes or renovations in mechanical system, transmission mode, signal setting, servo system, magnetic medium, etc, its standard bandwidth reaches 1.5 gmps, which is a regular” Post-PC” modern technology.
1sata technological basics
1.1 simplified design
The SATA serial link interface method obtains from the ISO/OSI as well as TCP/IP models and the concepts of things, service and ordered encapsulation, from low to high, there are four layers: physical layer, web link layer, transport layer as well as application layer. Because interaction is in between a host as well as a storage device that is not peer-to-peer, the conventional peer-to-peer entity depiction has altered.
1.2 the procedure state mechanism
The operation of SATA protocol is generally accomplished by Transportation State Maker and Link State Device, which are two core sub-modules of communication entity protocol stack, by breaking down the top operations right into a collection of activities that can be exchanged with the link state, the TCSM uses the sub-module sources in the user interface to complete the operations connected to the host platform. Both state devices work with each other in the process of information transmission and enhance the application sources.
1.3 improve as well as simplify core technologies
Sata is a high-speed serial bus innovation. In order to accomplish higher information transfer price than identical 16 information lines on just 4 information lines, it decreases method power structure, simplifies procedure content and algorithm intricacy High-speed or transmission-friendly modern technologies are greatly utilized at each layer. These technologies consist of:
Frame modern technology SATA utilizes framework as the basic transmission system, sustaining seven kinds of framework transmission, the optimum length of 8192 bytes. In the framework framework, the HOLD, Holda (32-bit) primitives are used for flow control, and FIS Material is the haul.
NCQ  (NCQ-native Command Queuing) is a powerful disk user interface innovation presented in SATA I to decrease host-device handshakes, aggregate information disrupts, as well as user interface transactions. It can decrease the mechanical setting delay of looking for and revolving of the motorist as well as boost the efficiency of the line up load. NCQ is the just one of the many functional expansions to SATA 1.0 that is carefully pertaining to efficiency. NCQ takes on RPO disk turning command organizing formula, supports thread and up to 32 levels of command queue management, and adds 3 new capacities: Race-free state return system, interrupt gathering and First Parity DMA.
:: point-to-point connection the SATA storage device is linked to the host in a point-to-point connection as well as celebrity geography with committed data transfer, which minimizes the complexity of shared adjudication and arrangement as well as prevents a solitary point of failure, improved scalability as well as concurrency.
Full-level error discovery is supported in the SATA method stack, and also error detection prolongs from the lower degree to the leading degree  Errors in between layers are gone through the interface state register and the interface error register, as well as each layer has the ability to detect, control, and recuperate from errors. Relying on the nature and also recoverability of the mistake, there are four handling strategies: Freeze, Abort, Retry, and also Track/Ignore.
:: The improved wire port and the signal and also power cables of the hot-plug  Sata are configured independently and also are separated by ground cables between the signal or power cables. Blind matching style, head with added extending for plug location and defense; assistance for out-of-band hard disk discovery, complete hot plug assistance.
Other strategies SATA uses alphabetical tokens to describe data bits and control variables, as well as 8b/10B encoding is used to translate unencoded data and also control bytes from SATA into strings. The transmitted signal utilizes low-voltage differential (LVD-RRB- modern technology suitable with existSCSISCSI circuits (countered 250 mv). Power management granularity, it can not just the storage device power administration, however additionally has a self-management function, can not run part of the low-power mode.
2sata application service
Serial storage devices are located on desktops as well as low-and medium-end network storage, in order to be able to establish applications in locations dominated by these parallel interfaces, the sector has actually followed the traditional” Parallel-string compatibility coexistence, the gradual shift to pure serial” method. Currently, the mainstream option to execute this technique is bridge. Sata/Pata Bridge is based upon the existing system bus. By adding the SATA/PATA converter card, the serial/parallel conversion is recognized, as well as the sophisticated serial tools are incorporated right into the identical structure environment.
Today, bridge is an ideal and also convenient remedy to address the conjunction of SATA and Pata in the system, which has the advantages of not influencing the initial system, short development cycle, and so on, it enhances cost, board area, and also power usage, along with the intricacy of driver PCB design and also production, so it can only be made use of as a transitional solution.
2.2 local equipment
The technique is to connect the SATA hard drive directly into the system framework, omitting a large number of transitions and plan delays in the bridge mode, so as to optimize the practical qualities of SATA. AHCI  (Advanced Host Controller Interface) is a perfect option for carrying out a regional device policy with indigenous SATA performance using the PCI BAR (Base Address Register).
AHCI is essentially a PCI-like gadget that serves as a common interface in between the system memory bus and the internal reasoning of the serial ATA device. This course tool explains a common system memory framework with control as well as status locations, command series entrance tables; each command entry consists of SATA device shows info, and also a pointer to the summary table (for moving data on the gadget as well as host).
The local gadget system is understood by integrating SATA right into chipset. It can maximize the benefits of SATA to minimize the variety of signals, reveal the broadband of SATA, save the board area, increase the reliability and decrease the power usage, much easier to apply. The downside is that SATA interface is a high-speed signal, which brings interference to the analysis network, so it is required to take proper Signal integrity protection gauges right into factor to consider when creating chips as well as motherboards. The successful growth of the AHCI unified user interface streamlines the development of items that support serial ATA, as well as removes the need for running system and device manufacturers to develop user interfaces separately, rather, it operates straight on the merged interface, allowing it to carry out numerous functions, consisting of NCQ.
2.3 comparison of bridge and also regional equipment plans
Along with the technical substantive distinctions described above, the bridge as well as regional devices plan has several differences as shown in Table 1. From the contrast, we can also see the limitation of the bridge to the SATA assistance, which reveals the concession of the innovation to the status, as well as it is destined that the bridge belongs to the product of the transitional phase of the technology growth.
3sata device programming
3.1 SATA information stream
In SATA systems, data adjustment items are divided into Primitive, FIS, and Command by granularity. Information is exchanged between the (host) adapter and also the storage device, and also the things as well as data framework connections involved in the exchange  are displayed in Number 1. In the layout, the arrowhead factors from the moms and dad object to the kid item, as well as the numbers 1 as well as N stand for the number of youngster objects possessed by the parent things. The adapter item represents a control board, or HBA, as well as it has an adapter info data framework pertaining to the adapter. The adapter can have multiple controllers, each with its own independent controller info, consisting of the controller usual register information framework and also various other control details. Each controller has several ports for linking to the target gadget. Each port attaches to a storage device that has a queue of commands of depth 1 or greater, as well as each command is represented by command things related to information frameworks and DMA things. In addition, for some storage devices with several ports, permit it to attach to the port of one more controller to enhance the schedule as well as reliability of the gadget.
3.2 Sata programming framework
The programs framework of SATA is shown in Figure 2( where to the right is the pecking order of API connections), the details os module (1 in Figure 2) completes the translation of low-level motorist requests from various os right into a style that the low-level tool can recognize. The SATA collection component (2 in Number 2) includes 2 elements, basic SATA logic as well as SATA control logic, offering typical operating system-independent apis for chauffeur components of various operating systems. Among them, the General Sata reasoning module is independent of the controller, operating system and framework, the major application of all the formulas as well as regimens. Sata control logic describes all the special controller code, the particular material depends upon the main controller chip. The operating system services layer (3 in Number 2) offers an operating system-independent user interface to the SATA library layer. It is related to the specific operating system, as well as can convert the demand of the upper os course into the demand layout that the target operating system can recognize.
3.3 running system support for SATA applications
3.3.1 Windows system
In Windows system, the bridge is realized by simulating the PATA pattern controller sustained by Windows, packing and making use of the PATA controller. To sustain both SATA settings, Microsoft has established Ataport to support the most up to date ATA/ATAPI command set, which sustains a PATA/SATA crossbreed application atmosphere. The SATA controller developed by Ataport generally offers 2 miniports, among which is the default Miniport vehicle driver sustaining the current PATA controller, replacing the existing and also the driving stack feature entity of the SATA simulation PATA; The various other is a microport driver that sustains AHCI SATA to carry out native tool setting in future Windows systems. In Ataport, the functioning mode of each gadget is established by subclass code of Base Class 01( Block Memory) in the PCI requirements, which is set to 01H when the SATA tool is running in imitated parallel setting; When running in regional SATA setting, it needs to be readied to 06h. To Be Clear, Windows 2003 Server and all previous versions do not give support for regional gadgets.
3.3.2 Linux platform
The Linux system supports SATA tools by obtaining from mature PATA and also enhancing the different parts of PATA and SATA to extend some brand-new functions implemented by SATA.
IDE device driver component (IDE.C) contains some details gadget sub-drivers such as IDE-pci. C, ide-probe. C, ide-pnp. C, ide-dma. C, ide-proc, etc. According to the brand-new qualities of SATA, the physical discovery and transmission of SATA gadgets are boosted, that is, the ide-probe of the initial Pata. C, ide-dma. C sub-drives and so on are modified, other sub-drives can attract straight from Pata. The user just needs to recognize the assistance of both bridge as well as neighborhood modes through the optional setup of the drive layer.
4 development fad
SATA is a new bus technology as well as a perfect replacement modern technology of PATA. The study and also application of SATA has become a pattern. The pattern is shown in:
( 1) the standardization work will certainly be accelerated even more. The Sata functioning group, Intel, Seagate, Maxtor, IBM, and so on, which lead the standardization work of SATA, are continuously improving the SATA criteria, there are variations of SATA 1.0(A, B, C, D, and so forth), Sata I (Extensions to Serial ATA 1.0 A, revision 1.1), and so on. On 6 Might 2004, the Serial ATA Working Team included the 3 Gbps physical layer data transfer originally presented in the 2nd generation into the Serial ATA II requirement. Compared to the fast progression of the new requirements, the speed of automation likewise requires to catch up quickly. Vital job is urgently required to merge the understanding of SATA communications and also capabilities amongst vendors of drives, motherboards, as well as pcs, particularly chip manufacturers, as well as to create a real plug-and-play as well as co-existence atmosphere.
( 2) hardware-based method, hardware-based procedure is an effective way to minimize the complexity and performance of the procedure, the hardware of some or all of the method features of the second and also third layers (incorporated into chipsets) will be the main means to recognize the SATA features.
( 3) the application of SATA will gradually transition to neighborhood setting. The bridge application mode is a low-cost and also completely compatible PATA environment plan in the process of PATA migrating to SATA. However, with the advancement of standardization as well as industrialization of SATA and AHCI, the current scenario of the coexistence of and SATA will slowly change to SATA-led.
( 4) Sata will certainly be used in network storage space. Sata has many benefits, such as high transmission capacity, extensible geography, data integrity, reliability, MTBF of disk is equal to that of SCSI, and also it sustains hot-swapping network storage space, it has the conditions to enter the field of network storage space with low-priced RAID. On top of that, SAS (Serial Installed SCSI) sustains SATA and supplies STP (Sata Passage Method) to be as suitable as feasible with Sata and so on, all of which supply technological problems for SATA to enter the field of network storage space.
With the intro of ATA-100/ 133, the growth of PATA has actually concerned an end. It is an inescapable trend to introduce Sata rather than. Sata presents a variety of brand-new innovations and keeps PATA compatibility. Windows and also Linux running systems offer application support, simple and also fast to establish applications. Getting a lot higher efficiency at relatively inexpensive than , as well as increasing area for medium-and low-end business storage space and other out-of-memory applications, will certainly be among the mainstream modern technologies in the future.