Maxtor 300 manual Solving the 137 Gigabyte Capacity Barrier, How is the Extension Implemented?

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Breaking the 137GB Storage Barrier

A.1.2 Solving the 137 Gigabyte Capacity Barrier

As described earlier, the issue causing the 137-gigabyte barrier is the 28- bit addressing method of the original ATA specification. A change to expand this method was required to provide more address bits for the interface, allowing significant growth for many years to come. A critical issue in expanding the addressing capability was maintaining compatibility with the existing installed base of products.

The new ATA standard, ATA/ATAPI-6, resolves this issue by increasing the maximum number of bits used for addressing from 28 to 48. This solution increases the maximum capacity of an ATA device to 144 petabytes while maintaining compatibility with current ATA products.

A.1.3 How is the Extension Implemented?

The 48-bit Address feature set provides a method to address devices with capacities up to approximately 144 petabytes by increasing the number of bits used to specify logical block addresses (LBAs) from 28 to 48. The feature set also provides a method to increase the number of sectors that can be transferred by a single command from 256 to 65,536 by increasing the number of bits specifying sector count to 16 bits.

New commands specific to this feature set have been defined so that devices can implement the new feature set in addition to previously defined commands. Devices implementing the 48-bit Address feature set commands will also implement commands that use 28-bit addressing in order to maintain interoperability with older system components. In addition, 8-bit and 48-bit commands may be intermixed.

The 48-bit Address feature set operates in LBA addressing only. Support of the 48-bit Address feature set is indicated in the IDENTIFY DEVICE response data. In a device implementing the 48-bit Address feature set, the registers used for addressing are, in fact, a two-byte deep FIFO. Each time one of these registers is written, the new content written is placed into the “most recently written” location and the previous content of the register is moved to “previous content” location. A host may read the “previous content” of the registers by first setting a bit in the Device Control register to 1 and then reading the desired register.

A.1.4 What Do the Drives Need to Meet the Spec?

The challenge to drive manufacturers is to develop and implement new interface chips on drives that can accept and decode the new 48-bit addressing scheme. Many functions of decoding the commands sent to and from the drive are automated in the silicon of the drive interface ASIC, and this is where drive manufacturers must update their designs. Maxtor is the leader in development efforts and is the first to deliver a product with the capacity and drive technology to deliver greater than 137 gigabytes of capacity.

Quickview 300 80/100/120/160/200/250/300GB PATA

A-3

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Contents MaxtorQuickview 80/100/120/160/200/250/300GB Pata Patents Publication Number Part Number Before You Begin McCarthy Blvd Milpitas, California Tel Fax Chapter InstallationChapter Introduction General DescriptionService and Support Product SpecificationsATA BUS Interface and ATA Commands Appendix a Breaking the 137 Gigabyte Storage BarrierList of Figures List of Tables Products Maxtor CorporationAudience SupportManual Organization Terminology and ConventionsMSB References KEY Features Product OverviewGeneral Description Regulatory Compliance Standards Product EMI/EMS QualificationsInstallation Space RequirementsUnpacking Instructions 2Quickview 300 20-Pack Shipping Container Pata Interface Connector Hardware Options1AT Jumper Options Cable Select CS JumperMaster Jumper Configuration Drive Select DS JumperPower On Standby Cylinder Limitation Jumper CLJ4AT Connector and Jumper Location Pata BUS Adapter Combination Connector J12.1 40-Pin Pata Bus Connector Adapter Board5J1 DC Power and Pata Bus Combination Connector External Drive Activity LED DC Power J1, Section aPata Bus Interface Connector J1, Section C Mounting Orientation Installation Ventilation Adapter Board InstallationClearance For Systems With a Motherboard Pata AdapterConnecting the Adapter Board and the Drive 8Drive Power Supply and Pata Bus Interface CablesTechniques in Drive Configuration Operating system limitationsDrive Configuration Models and CapacitiesPerformance Specifications Physical Dimensions Parameter ValueVoltage Tolerance Power Requirements for 80/100/120/160/200GB TypicalPower Requirements for 250GB/300GB Typical Power Mode Definitions EPA Energy Star ComplianceEnvironmental Limits Acoustic Noise11Baseplate Tempurature Measurement Location Shock and Vibration Parameter Operating NON-OPERATINGStart/Stop Cycles Reliability SpecificationsAnnualized Return Rate Data ReliabilitySafety Regulatory Compliance Canadian Emissions StatementMechanical Interface Signal Cable and ConnectorIntroduction Electrical InterfaceSupported Commands Command InterfaceGeneral Feature Set Command Feature Register Code ValuesFlush Cache SET Multiple Mode Write Sectors 30hContent Description Word10-19 Serial number 20 Ascii characters 20-21 Retired Content Description Minimum PIO transfer cycle time without flow control Minor version number See Address Offset Reserved Area Boot, Incits TR272001 = release interrupt enabled Supported Content Description Reserved 255 Integrity word 15-8 Checksum Signature Service and Support Product Support/Technical Assistance/Customer ServiceBreaking the 137 Gigabyte Storage Barrier HistoryDOS What Do the Drives Need to Meet the Spec? Solving the 137 Gigabyte Capacity BarrierHow is the Extension Implemented? Appendix a What is the Next Barrier?What Else is Involved? Appendix B Big Numbers Appendix CGlossary Glossary FCI Acronym for flux changes per inch. See also BPI Initialize See low level formatting Millisecond ms One thousandth of a second .001 sec Glossary Quickview 300 80/100/120/160/200/250/300GB Pata G-7 Glossary Index