LXT-200A Product Specification and OEM Technical Manual Document 1019708 Revision A October 1989 REVISION RECORD Revision Date Published Revised Contents A October 1989 Formal Release Document No: 1019708 WARRANTY Maxtor warrants the LXT-200Aª Family of disk drives against defects in materials and workmanship for a period of twelve months, for the original purchaser. Direct any questions regarding the warranty to your Maxtor Sales Representative. Maxtor maintains Customer Service Centers for the repair and reconditioning of all Maxtor products. Direct all requests for repair to the Maxtor Service Center in San Jose. This assures you of the fastest possible service. REGULATORY APPROVALS UL Recognition: File Number E87276 CSA Certification: File Number LR87443-1 TUV Certification: File Number R98179 Address comments concerning this manual to: Maxtor Corporation Technical Publications 211 River Oaks Parkway San Jose, California 95134-1913 Telephone: (408) 432-1700 Telex: 171074 FAX: (408) 434-6469 Technical Data Restrictions In case of sale to or use of units by DoD: Use, duplication or disclosure of any software, firmware or related documentation is subject to restrictions stated in paragraph (c) (1) (ii) of the Rights in Technical Data and Computer Software clause at DFAR 252.227-7013. For Civilian Agencies: Use, reproduction, or disclosure of the software and related documentation is subject to restrictions set forth in FAR 52.227-19. Unpublished rights reserved under the copyright laws of the United States. Maxtor Corporation, 211 River Oaks Parkway, San Jose, CA 95134. Copyright Notice This manual and all material contained in it are copyrighted. The manual may not be copied, in whole or in part, without the written consent of Maxtor Corporation. The contents of this manual may be revised without prior notice. © Copyright 1989 by Maxtor Corporation, San Jose, California, USA. All rights reserved PREFACE The purpose of this manual is to provide all of the technical information you need to install and use the Maxtor LXT-200A Family of disk drives. It is intended for evaluation and integration Engineers who are building or assembling a total computer system. This manual does not include the information needed to repair these drives. For this information contact the Maxtor Service Center in San Jose. Chapter 1 is a complete description of the drive, including specifications. Chapter 2 provides the information you need to prepare the drive for installation. Chapter 3 covers installation. Chapter 4 provides information on the physical interface of the drive. Chapter 5 covers the ATA register set. Chapter 6 covers the ATA command set. Maxtor publishes descriptive brochures and data sheets, this technical manual, and a quick reference guide for each product line. Changes that affect the content of any manual are covered by addenda or revisions to the affected manual. Maxtor reserves the right to make changes and/or improvements to its products without incurring any obligation to incorporate such changes or improvements in units previously sold or shipped. LXT-200A Product Specification & OEM Technical Manual TABLE OF CONTENTS LXT-200A Product Specification & OEM Technical Manual TABLE OF CONTENTS PREFACE.....................................................V 1.0....................................DISK DRIVE DESCRIPTION 1 1.1.............................Drive Features and Benefits 2 1.2..................................Product Specifications 4 1.2.1.........................Performance Specifications 4 1.2.2..........................Functional Specifications 5 1.2.3.......................Environmental Specifications 6 1.2.4............................Physical Specifications 7 1.2.5.........................Reliability Specifications 7 1.2.6........................................Error Rates 8 1.2.7................Error Correction Code Specification 8 1.2.8..................................Defect Management 8 1.2.9..............................DC Power Requirements 9 1.2.10.........................Standards and Regulations 9 1.3.............................................Major Parts 10 1.3.1..............................Air Filtration System 10 1.3.2....................................Drive Mechanism 11 1.3.3.........................Head Positioning Mechanism 12 1.3.4.........................Read/Write Heads and Disks 13 Doc 1019708, Rev A ix Maxtor Corporation Doc 1019708, Rev A ix Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual TABLE OF CONTENTS 2.0..........................................DISK DRIVE SETUP 15 2.1.................................................Jumpers 16 2.2.............................................Sector Size 16 2.3.......................................Service Connector 16 3.0...................................DISK DRIVE INSTALLATION 19 3.1................................................Mounting 19 3.2........................................Power-Up Testing 22 3.2.1.................................Self-Test Sequence 23 3.2.2............................Initialization Sequence 24 3.2.3.................................Self-Configuration 24 3.2.4...................................Buffering Scheme 24 3.3................................................Shipping 24 4.0........................................PHYSICAL INTERFACE 25 4.1....................................Host-Drive Interface 26 4.2.........................................Power Connector 28 4.3........................................Ground Connector 28 4.4.....................................Interface Connector 29 4.5.......................................Interface Signals 30 4.5.1................................Signal Descriptions 31 4.5.2.............................Signal Timing Diagrams 34 5.0..........................................AT-BUS REGISTERS 37 5.1....................................I/O Port Assignments 37 Doc 1019708, Rev A x Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual TABLE OF CONTENTS 5.2...................................Register Descriptions 39 5.2.1......................................Data Register 39 5.2.2.....................................Error Register 40 5.2.3...........................Precompensation Register 41 5.2.4..............................Sector Count Register 41 5.2.5.............................Sector Number Register 41 5.2.6..............................Cylinder Low Register 41 5.2.7.............................Cylinder High Register 41 5.2.8................................Drive-Head Register 42 5.2.9....................................Status Register 42 5.2.10..................................Command Register 44 5.2.11.........................Alternate Status Register 44 5.2.12...........................Digital Output Register 44 5.2.13............................Drive Address Register 45 5.3..........................................Reset Response 46 6.0...........................................ATA COMMAND SET 47 6.1.........................................Error Reporting 48 6.2..........................................Translate Mode 50 6.3....................................Command Descriptions 50 6.3.1...................EXECUTE DRIVE DIAGNOSTIC Command 51 6.3.2...............................FORMAT TRACK Command 52 6.3.2.1......................Format Sectors as Good/Bad 53 6.3.2.2............................Reassign Bad Sectors 53 6.3.3.............................IDENTIFY DRIVE Command 54 Doc 1019708, Rev A xi Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual TABLE OF CONTENTS 6.3.4................INITIALIZE DRIVE PARAMETERS Command 56 6.3.5................................READ BUFFER Command 57 6.3.6..............................READ MULTIPLE Command 57 6.3.7.............................READ SECTOR(S) Command 58 6.3.8................................RECALIBRATE Command 58 6.3.9.......................................SEEK Command 59 6.3.10...........................SET BUFFER MODE Command 59 6.3.11.........................SET MULTIPLE MODE Command 59 6.3.12..........................VERIFY SECTOR(S) Command 60 6.3.13..............................WRITE BUFFER Command 60 6.3.14............................WRITE MULTIPLE Command 60 6.3.15...........................WRITE SECTOR(S) Command 61 APPENDIX A: CDB BIT DEFINITIONS...........................63 APPENDIX B: UNITS OF MEASURE..............................65 GLOSSARY...................................................67 Doc 1019708, Rev A xii Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual FIGURES LXT-200A Product Specification & OEM Technical Manual FIGURES Figure 1ú1................................LXT-200A Disk Drive 1 Figure 1ú2..............................Air Filtration System 11 Figure 1ú3.........................Head Positioning Mechanism 12 Figure 2ú1.........................................PCB Layout 15 Figure 2ú2...........Connector Locations, Front View of Drive 17 Figure 3ú1..........Mechanical Outline, Bottom and Side Views 20 Figure 3ú2.................Mechanical Outline, Isometric View 21 Figure 3ú3................................Removable Faceplate 22 Figure 4ú1..........................Host-Drive Configurations 25 Figure 4ú2...............................Host-Drive Interface 27 Figure 4ú3................................Interface Connector 29 Figure 4ú4............Connector Locations, Rear View of Drive 30 Figure 4ú5....Interface 16 Bit Data Transfer to or from Drive 35 Figure 4ú6.......................................Reset Timing 35 Doc 1019708, Rev A xiii Maxtor Corporation Doc 1019708, Rev A xiii Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual TABLES LXT-200A Product Specification & OEM Technical Manual TABLES Table 1ú1..........................Performance Specifications 4 Table 1ú2...........................Functional Specifications 5 Table 1ú3................................Environmental Limits 6 Table 1ú4.................................Physical Dimensions 7 Table 1ú5..........................Reliability Specifications 7 Table 1ú6.........................................Error Rates 8 Table 1ú7...............................DC Power Requirements 9 Table 2ú1...............................Jumper Configurations 15 Table 2ú2...................Service Connector Pin Assignments 17 Table 3ú1.........................Initial Values of Registers 23 Table 4ú1.....................................Power Connector 28 Table 4ú2........................Power Connector Mating Parts 28 Table 4ú3....................Interface Connector Mating Parts 30 Table 4ú4...................................Interface Signals 32 Table 4ú5....................................Interface Timing 36 Table 5ú1................................I/O Port Assignments 38 Table 5ú2...................Selection Addresses and Functions 39 Table 5ú3..............................Error Bits in Register 40 Table 5ú4.................................Drive-Head Register 42 Table 5ú5................................Status Register Bits 42 Table 5ú6......................Alternate Status Register Bits 44 Table 5ú7...............................Digital Register Bits 44 Table 5ú8.........................Drive Address Register Bits 45 Doc 1019708, Rev A xv Maxtor Corporation Doc 1019708, Rev A xv Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual TABLES Table 5ú9.............................Initial Register Values 46 Table 6ú1.............Summary of Commands and Parameters Used 47 Table 6ú2...............................Valid Error Responses 49 Table 6ú3.........................................Error Codes 51 Table 6ú4............................Interleave Table Example 52 Table 6ú5....................................Flag Byte Values 52 Table 6ú6..............Format of Drive Parameters Information 55 Table 6ú7...............General Configuration Bit Definitions 56 Table 6ú8.........Initialize Drive Parameters Register Values 56 Doc 1019708, Rev A xvi Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual LXT-200A Product Specification & OEM Technical Manual Doc 1019708, Rev A 1 Maxtor Corporation Doc 1019708, Rev A 1 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 1.0 DISK DRIVE DESCRIPTION The LXT-200A disk drives are high capacity, high performance, random access storage devices which use nonremovable 3.5-inch disks as storage media. Each disk surface employs one moveable head to access the data tracks. See Figure 1ú1, LXT-200A Disk Drive. The total formatted capacity of each drive is 201 megabytes at 512 bytes per sector. The unformatted capacity is 234 megabytes. The drive is designed to operate in an IBM PC/AT or compatible computer. The host interface uses a task file structure which is the standard interface for PC/AT rigid disk controllers. Because the host interfaces with the drive directly through the task file register, an address decoder or buffer control logic is required either in the mother board or in an adapter board. Figure 1ú1 LXT-200A Disk Drive These disk drives include the Advanced Technology Attachment (ATA) interface controller embedded in the drive electronics. Some of the resulting benefits of having an integrated controller include the elimination of a separate controller printed circuit board (PCB), reduction in the number of associated cables, and elimination of the controller-specific power supply. High performance is achieved through the use of a rotary voice coil actuator and a closed loop servo system using a dedicated servo surface. The innovative MAXTORQª rotary voice coil actuator provides performance usually achieved only with larger, higher powered linear actuators. The closed loop servo system and dedicated servo surface combine to allow state-of- the-art recording densities (1,591 tracks per inch, 28,910 bits per inch) in a 3.5-inch package. High capacity is achieved by a balanced combination of high areal recording density, run-length limited (RLL) data encoding techniques, and high density packaging techniques. A three-zone implementation of 1,7 code is used. Maxtor's advanced MAXPAKª electronic packaging techniques use miniature surface-mounted devices to allow all electronic circuitry to fit on one PCB. Doc 1019708, Rev A 2 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual Advanced flexures and heads allow closer spacing of disks, and therefore allow a higher number of disks in a 3.5-inch package. Maxtor's integrated drive motor and spindle design allows a deeper head disk assembly (HDA) casting than conventional designs, thus permitting four disks to be used. The drive's size and mounting conform to the industry standard 3.5-inch form factor for floppy and Winchester disk drives, and the same direct current (DC) voltages and connectors are used. 1.1 DRIVE FEATURES AND BENEFITS Some key disk drive features include: FEATURE BENEFITS ú Storage capacity of 201 Maximum storage in the megabytes, formatted at 3.5-inch disk drive 512 bytes per sector market; good upgrade from (234 megabytes, the 5.25-inch disk drives unformatted) which have less than 200 megabytes of capacity ú Single PCB for servo, High reliability, ease of read/write channel, and maintenance controller functions ú Thin film metallic media Higher bit density and resolution, plus improved durability ú Brushless DC spindle Maximum storage capacity motor inside hub ú Industry standard DC No AC power required, ease power supply re- of integration quirements ú Industry standard Ease of integration physical size and mounting ú Low 10 watts power Less current requirements dissipation of the power supply; low power use Doc 1019708, Rev A 3 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual Some key controller features include: ú AT task file register compatible command set ú Extended command set support system auto- configuration, self-diagnostic and media certification ú Sophisticated and efficient address translation, allowing full usage of the zone bit encoding capacity ú Address translation to maintain compatibility down to the BIOS and register level ú Programmable 56-bit error correction code (ECC) ú Interleave of 1:1 supported ú 32 kilobytes dual-ported buffer; two full tracks capacity ú High performance buffer manager that is capable of disk and host transfers at the same time ú Dedicated 16-bit microprocessor ú Error map on disk ú Standard 40 pin task file interface ú Two drives may be daisy-chained on the interface and configured as one Master and one Slave. ú Sophisticated read-ahead caching utilizing the 32 kilobyte buffer to maximize data through put. ú Multiple sector transfers are supported to reduce system overhead on data transfers The commands supported by the drive are listed and discussed in chapter 6, ATA Command Set. Doc 1019708, Rev A 4 Maxtor Corporation 1.2 PRODUCT SPECIFICATIONS This section includes specifications for performance, function, environmental limits, physical dimensions, reliability, error rates, error correction code, and DC power requirements. At the end of this section is a list of the standards and regulations that apply to this family of drives. 1.2.1 Performance Specifications Table 1ú1 Performance Specifications 1.2.2 Functional Specifications Table 1ú2 Functional Specifications 1.2.3 Environmental Specifications Table 1ú3 Environmental Limits 1.2.4 Physical Specifications Table 1ú4 Physical Dimensions 1.2.5 Reliability Specifications Table 1ú5 Reliability Specifications 1.2.6 Error Rates Table 1ú6 Error Rates 1.2.7 Error Correction Code Specification The forward ECC polynomial is as follows: X56+X52+X50+X43+X41+X34+X30+X26+X24+X8+1. The reverse ECC polynomial is as follows: X56+X48+X32+X30+X26+X22+X15+X13+X6+X4+1. 1.2.8 Defect Management A complicated flaw scan process to generate the defect list is done at the factory for every drive. As shipped from the factory, the drive is pre-formatted with all defects reassigned to spare sectors. When reassigning defect sectors, the track is laid out again so that the defect area is skipped. One-to-one interleave and skewing factors are rearranged to maintain the streaming performance. The drive is assumed to be error-free after formatting. 1.2.9 DC Power Requirements Table 1ú7 DC Power Requirements 1.2.10 Standards and Regulations The Maxtor LXT-200A disk drives are intended to satisfy the following standards and regulations: UNDERWRITERS LABORATORIES (UL) is United States safety; UL 478, Standard for Safety, Electronic Processing Units and Systems. CANADIAN STANDARDS ASSOCIATION (CSA) is Canadian safety; CSA C22.2 No. 220, 1986, Information Processing and Business Equipment (Consumer and Commercial Products). INTERNATIONAL ELECTROTECHNICAL COMMISSION (IEC) is International safety commission; IEC 950 (formerly 380), Safety of Information Technology Equipment. FEDERAL COMMUNICATIONS COMMISSION (FCC) is United States radiation emissions; Part 15, Subpart J, Class B Consumer Computing Devices. CAUTION: This equipment generates and uses radio frequency energy, and may cause interference to radio and television reception if not installed and used in strict accordance with the instructions in this manual. The drive has been tested and found to comply with the limits for a Class B computing device, in accordance with the specifications in Subpart J of Part 15 of FCC Rules, which are designed to provide reasonable protection against radio and television reception interference in a residential installation. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference using one or more of the following measures: ú reorient the receiving antenna ú reorient the computer with respect to the receiver ú move the computer away from the receiver ú plug the computer into a different outlet, so that the computer and receiver are on different branch circuits If necessary, consult the dealer, or an experienced radio/television technician, for additional suggestions. You may find the FCC booklet How to Identify and Resolve Radio TV Interference Problems helpful. This booklet is available from the United States Government Printing Office, Washington, D.C., 20402, stock number 004-000- 00345-4. Maxtor is not responsible for any radio or television interference caused by unauthorized modifications to the drive. It is the responsibility of the user to correct such interference. 1.3 MAJOR PARTS The major elements of the drive are the air filter, the head amplifier, the positioning motor, the read/write head assembly, and the spindle motor. See Figure 1ú1, LXT-200A Disk Drive. A brief discussion of some of these parts appears below, in alphabetical order. 1.3.1 Air Filtration System The disks and read/write heads are assembled in a Class 100 environment and then sealed within the head disk assembly (HDA). The HDA contains an absolute filter, mounted inside the casting, to provide constant internal air filtration. See Figure 1ú2, Air Filtration System. Figure 1ú2 Air Filtration System 1.3.2 Drive Mechanism The HDA is a sealed subassembly containing the mechanical portion of the drive. A brushless DC motor contained within the spindle hub rotates the spindle and is con- trolled by a dedicated microprocessor. The motor and spindle are dynamically balanced to ensure a low vibration level. Shock mounting is provided internally in the HDA to minimize transmission of vibration through the frame. The frame is the mechanical assembly holding the HDA and printed circuit board (PCB). 1.3.3 Head Positioning Mechanism The read/write heads are mounted on a head/arm assembly, which is then mounted on a ball bearing supported shaft. See Figure 1ú3, Head Positioning Mechanism. The voice coil, an integral part of the head/arm assembly, lies inside the magnet housing when installed in the drive. Current from the power amplifier, controlled by the servo system, induces a magnetic field in the voice coil which either aids or opposes the field around the permanent magnets. This reaction causes the voice coil to move within the magnetic field. Since the head/arm assemblies are connected to the voice coil, the voice coil movement is transferred, through the pivot point, directly to the heads, to position them over the desired cylinder. Figure 1ú3 Head Positioning Mechanism Actuator movement is controlled by the servo feedback signal from the servo head. The servo information is prewritten at the factory, and is used as a control signal for the actuator to provide track crossing signals during a seek operation, track following signals during on cylinder operation, and timing information, such as index and servo clock. The servo information also provides the timing to divide a track into sectors used for data storage. The servo control system has a dedicated microprocessor for fast, optimized performance. 1.3.4 Read/Write Heads and Disks The drive employs state-of-the-art sliders and flexures. The configuration of the sliders and flexures provides improved aerodynamic stability, superior head to disk compliance, and a higher signal-to-noise ratio. The media uses a nickel-cobalt metallic film that yields high amplitude signals and very high resolution performance compared to conventional oxide coated media. It also provides an abrasion and impact resistant surface, decreasing the potential for damage caused by shock and vibration during shipping. The data on each of the media surfaces is read by one read/write head. There is one surface dedicated to servo information in each drive. LXT-200A Product Specification & OEM Technical Manual LXT-200A Product Specification & OEM Technical Manual Doc 1019708, Rev A 1 Maxtor Corporation Doc 1019708, Rev A 1 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 2.0 DISK DRIVE SETUP Jumper locations are identified in Figure 2ú1, PCB Layout and Table 2ú1, Jumper Configurations. Figure 2ú1 PCB Layout Table 2ú1 Jumper Configurations 2.1 JUMPERS A ten pin header is provided that allows for installing or removing jumpers to configure the drive. The drive is shipped configured for use in a single drive system. Selection of the master drive is made by removing the master/slave jumper. Selection of the slave drive is made by installing the master/slave jumper. Installing the drive active jumper provides a current source for a drive active LED to pin 39 of the interface. If the slave present jumper is installed, the drive active jumper must not be installed. Installing the slave present jumper provides an output on DASP- that the slave drive is present. If the drive active jumper is installed, the slave present jumper must not be installed. The slave present jumper is not needed if both drives in the system are the LXT-200A. Installing the two drive system jumper on the master drive indicates that a slave drive is present. The manufacturing jumper is for internal use only. Installing this jumper may result in damage to the drive and loss of data. Doc 1019708, Rev A 2 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 2.2 SECTOR SIZE The drive is shipped from the factory formatted with 512- byte sectors. The sector size is not changeable. 2.3 SERVICE CONNECTOR Connector J4 in Figure 2ú2, Connector Locations, Front View of Drive, is a service connector providing the RS-232 interface and the ability to carry the LED signal beyond the drive. The RS-232 is used to load new firmware updates to the drive. The service connector is a ten-pin part. The mating connector is a Berg 6976410 part. Figure 2ú2 Connector Locations, Front View of Drive Pin assignments are as in Table 2ú2, Service Connector Pin Assignments (also see Figure 4ú4, Connector Locations, Rear View of Drive). Table 2ú2 Service Connector Pin Assignments When an LED is connected to pin nine (+) and pin ten (-), that LED functions in the same manner as the LED which is mounted on the drive's faceplate. This is typically used in cases where the drive is mounted in a position where the drive's LED is not visible and the faceplate is removed. Pins two through four are the RS-232 lines used to down load firmware updates to the microprocessor which are then stored on the disk. Pins three (transmit data) and four (receive data) are the main communication lines. Pin two is used to debug the processor and for a non-maskable interrupt. Pins five and six are signal ground lines. Doc 1019708, Rev A 3 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual LXT-200A Product Specification & OEM Technical Manual Doc 1019708, Rev A 1 Maxtor Corporation Doc 1019708, Rev A 1 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 3.0 DISK DRIVE INSTALLATION This chapter includes the information you need to install the drive, specifically mounting and shipping considerations. 3.1 MOUNTING The drive may be mounted in any orientation. In any final mounting configuration, ensure that the operation of the three shock mounts, which isolate the HDA from the frame, are not restricted. Certain switching power supplies may emanate electrical noise, which can degrade the specified read error rate. For best results, orient the drive so that the PCB assembly is not adjacent to these noise sources. Eight mounting holes, four on the bottom and two on each side, are provided for mounting the drive into an enclosure. The size and location of these holes, shown in Figure 3ú1, Mechanical Outline, Bottom and Side Views, are identical to industry standards. Overall height, width, and depth, along with other key dimensions, are shown in Figure 3ú1, and Figure 3ú2, Mechanical Outline, Isometric. Figure 3ú1 Mechanical Outline, Bottom and Side Views Figure 3ú2 Mechanical Outline, Isometric View The faceplate is clipped to the front of the HDA and may be removed in installations that do not require it. Lift up on the faceplate clips and unplug the LED cable from the PCB, as shown in Figure 3ú3, Removable Faceplate. Figure 3ú3 Removable Faceplate Doc 1019708, Rev A 2 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 3.2 POWER-UP TESTING This section describes the sequence of events during drive self-test and initialization sequences. The self-test sequence is performed upon power up, and is followed by the initialization sequence. NOTE: The self-test sequence can also be initiated via the EXECUTE DRIVE DIAGNOSTIC command which includes options for more comprehensive diagnostics. When the drive is reset, either by the host reset interface pin, -RESET, or by the SRST bit the drive sets the busy (BSY) bit immediately. Once the -RESET has been removed and the drive has been reenabled, with the BSY bit still set, the drive performs any necessary hardware initialization, clears any previously programmed drive parameters and reverts to the default condition, loads the command block registers with their initial values, and then clears the BSY bit. No interrupt is generated when initialization is complete, and no self test is performed. The initial values (hex) for the command block registers are shown in Table 3ú1. Table 3ú1 Initial Values of Registers 3.2.1 Self-Test Sequence The self-test sequence is executed upon drive power up. The self-test sequence verifies the integrity of the hardware. This test is not an exhaustive hardware diagnostic, but simply checks the major components for full function. After the self-test is complete and the circuitry is initialized (approximately 3 seconds), the drive loads the task file registers with the results of the self-test sequence, and clears the BSY bit. The self-test sequence consists of the following events: ú Hardware Reset Test - This routine tests the microprocessor, buffer controller, and disk formatter. If any of these tests fail, the disk drive can only be reset by a power up. ú Microprocessor Test - This routine tests the microprocessor's internal memory, timers, and register bank switching for proper operation. Doc 1019708, Rev A 3 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual ú Buffer Controller Test - This routine tests the buffer controller for proper operation. All the registers are tested and the chip is engaged to access random-access memory (RAM). ú Disk Formatter Test - This routine tests the disk formatter chip by writing and reading all possible patterns to each of the disk formatter chip registers. After the registers are tested, the interrupts are tested to ensure that the formatter chip generates an interrupt when a command completes. If any portion of the self-test fails, except the hardware reset test, the drive can be reset by a power up reset. The failure of the hardware reset test is considered a catastrophic failure and the controller can only be reset from such a failure by a power up reset. If the drive fails, the result is set in the task file register. 3.2.2 Initialization Sequence The initialization sequence is executed for any one of the following three reasons: ú A power up sequence occurs. ú The -RESET signal is asserted. ú The BSY bit is set until the self-test is done and then it is cleared. 3.2.3 Self-Configuration When the drive powers up or is reset, it configures itself in accordance with its default general drive parameters. See Table 6ú6. 3.2.4 Buffering Scheme The disk drive buffer is a 32-kilobyte FIFO buffer. There are 32,767 bytes available for data storage. The buffer controller allows transfer to the disk and from the host simultaneously, or from the disk and to the host simultaneously. 3.3 SHIPPING At power down, the heads are automatically positioned over the nondata, dedicated landing zone on each disk surface. The automatic shipping lock solenoid is also engaged at this time. Maxtor ships the drive in single and multipack shipping containers. Users can ship the drive installed Doc 1019708, Rev A 4 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual when the nonoperating shock and vibration limits are not exceeded. Doc 1019708, Rev A 5 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual LXT-200A Product Specification & OEM Technical Manual Doc 1019708, Rev A 1 Maxtor Corporation Doc 1019708, Rev A 1 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 4.0 PHYSICAL INTERFACE This chapter describes the interface requirements of the LXT-200A, which is compatible with the AT-BUS. Data is transferred in a 16-bit wide parallel data path from the host to the drive. Data transfer is controlled by commands sent from the host. The drive performs all operations necessary to write data on or read data from the medium. Data read from the medium is placed in a buffer prior to being transferred to the host. This document describes the capabilities necessary to operate the AT-Bus in a daisy chain configuration. This allows two drives to be connected to the host. The primary drive is designated as the master drive and the secondary drive is designated as the slave drive. See Figure 4ú1, Host-Drive Configurations. Figure 4ú1 Host-Drive Configurations 4.1 HOST-DRIVE INTERFACE The host-drive interface consists of single-ended TTL compatible receivers and drivers connected with a 40- conductor flat-ribbon cable. The maximum cable length is twenty-four inches (0.61 meter) when using an asynchronous protocol. Figure 4ú2, Host-Drive Interface, shows the pin numbers and signal names of the host and the drive. Figure 4ú2 Host-Drive Interface 4.2 POWER CONNECTOR The drive receives power through a four-pin keyed connector, drive connector terminal AMP P/N 61664-1 and cable connector terminal AMP P/N 62137-2. The power connector is shown in Table 4ú1. The recommended part numbers for the mating connector are given in Table 4ú2. Equivalent parts may be used. Doc 1019708, Rev A 2 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual Table 4ú1 Power Connector Table 4ú2 Power Connector Mating Parts 4.3 GROUND CONNECTOR Logic ground and chassis ground are tied together and an insert description lug is provided for connection to system ground. 4.4 INTERFACE CONNECTOR The interface connector is a 40-pin dual-row header connector (see Figure 4ú3). The connector is oriented as shown in Figure 4ú4. A key for the mating cable connector is provided by the removal of pin 20. The corresponding pin on the cable connector should be plugged. The cable connector should be keyed to prevent the possibility of installing it upside down. Figure 4ú3 Interface Connector Figure 4ú4 Connector Locations, Rear View of Drive Recommended part numbers for the mating connector and cables are shown in Table 4ú3. Equivalent parts may be used. Table 4ú3 Interface Connector Mating Parts Doc 1019708, Rev A 3 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 4.5 INTERFACE SIGNALS Signal names are shown in all upper case letters. Signals can be asserted (active, true) in either a high (more positive voltage) or low (less positive voltage) state. A dash character (-) at the beginning or end of a signal name indicates it is asserted at the low level (active low). No dash or a plus character (+) at the beginning or end of a signal name indicates it is asserted high (active high). An asserted signal may be driven high or low by an active circuit, or it may be allowed to be pulled to the correct state by the bias circuitry. Control signals that are asserted for one function when high and asserted for another function when low are named with the asserted high function name followed by a slash character (/), and the asserted low function name followed with a dash (-). For example, BITENA/BITCLR- enables a bit when high and clears a bit when low. All signals are TTL compatible unless otherwise noted. Negated means that the signal is driven by an active circuit to the state opposite to the asserted state (inactive, or false) or may be simply released (in which case the bias circuitry pulls it inactive, or false), at the option of the implementer. 4.5.1 Signal Descriptions Table 4ú4 describes the drive interface signals and pins. The signals are listed according to function, rather than in numerical connector pin order. The table lists signal name mnemonic, connector pin number, and whether the signal is an input to or output from the drive. Following the table is a description of each signal. Table 4ú4 Interface Signals Drive Reset: Reset signal from the host system which is asserted during power and negated thereafter. Drive Data Bus: A 16-bit bi-directional data bus between the host and the drive. The lower 8 bits are used for register and ECC byte access. All bits are used for data word transfers. The drive data bus uses 24 mA tri-state drivers. Drive I/O Write: A write strobe, the rising edge of which clocks data from the host data bus, DD0 through DD15, into a register or the data port of the drive. Doc 1019708, Rev A 4 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual Drive I/O Read: A read strobe, the falling edge of which enables data from a register or the data port of the drive onto the host data bus, DD0 through DD7 or DD0 through DD15. The rising edge of DIOR- latches data at the host. Drive Address Latch Enable: The drive address latch enable signal is not used on the LXT-200A. Drive Interrupt Request: An interrupt to the host system, asserted only when the drive CPU has a pending interrupt, the drive is selected, and the host asserts the IEN- bit in the digital output register. When the IEN- bit is negated, or the drive is not selected, this output is in a high impedance state, regardless of the presence or absence of a pending interrupt. The drive interrupt request signal uses 24 mA tri-state drivers. The interrupt is reset by a host read of the status register or a host write to the command register. I/O Control Select 16: An indicator to the host system that the 16-bit data port has been addressed and that the drive is prepared to send or receive a 16-bit data word. The I/O control select uses 24 mA tri-state drivers. Drive Address Bus: A three-bit binary coded address supplied by the host when accessing a register or the data port in the drive. Passed Diagnostic: This signal is an input, for the controller designated as a master, and is an output for the controller designated as a slave. It is used to indicate that a controller has successfully passed the diagnostics. Upon the receipt of an EXECUTE DRIVE DIAGNOSTICS command or the assertion of the -RESET signal, the slave controller will set this line high. If the command is completed without error, the slave will then negate the PDIAG signal to indicate to the master controller (which has this pin programmed as an input) that the slave has passed diagnostics or completed the reset. The master controller must wait a maximum of 5 seconds from the receipt the EXECUTE DRIVE DIAGNOSTIC command or 3 msec after a reset to allow the slave's report of status in the multi-controller mode (DASP- asserted). In single controller applications, the master will report status immediately after completion, terminating the command. Chip Select 1: The chip select signal is used to select the command block registers. Chip Select 3: The chip select signal is used to select the control block registers. Doc 1019708, Rev A 5 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual Drive Active or Slave Present: The use of this signal depends on the setting of jumper W2. This signal indicates either drive active or slave present. During a power-up and drive initialization, this line is an output from a slave drive, and an input to a master drive, indicating a slave drive is present. If the drive is a master, this line is an output which is asserted when the drive is selected and being accessed (BSY is set), and may be used to drive an activity LED. This is a 20 mA open collector output. Ground: Signal ground returns for the interface lines. Key Pin: Pin used for keying the interface connector. Reserved: These pins are currently defined as reserved and are not connected in the drive. 4.5.2 Signal Timing Diagrams Figure 4ú5, and 4ú6 show timing diagrams which define relationships between the interface signals. Timing standards are given for both 16 bit and 8 bit data transfers in Table 4ú5. Note that these are minimum acceptable interface timing requirements. Figure 4ú5 Interface 16 Bit Data Transfer to or from Drive Figure 4ú6 Reset Timing Table 4ú5 Interface Timing Doc 1019708, Rev A 6 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual LXT-200A Product Specification & OEM Technical Manual Doc 1019708, Rev A 1 Maxtor Corporation Doc 1019708, Rev A 1 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 5.0 AT-BUS REGISTERS The LXT-200A drive is programmed by the host computer to perform commands and return status to the host at command completion. When two drives are daisy chained on the interface, commands are written in parallel to both drives, and for all except diagnostic commands, only the selected drive executes the command. With diagnostic commands, both drives execute the command and the slave drive reports its status to the master drive via the PDIAG- signal. The drive selected is determined by the DRV bit in the drive-head register (see section 5.2.8), and by a jumper on the drive designating it as either a master or slave. The LXT-200A also provides a jumper on the master drive that indicates the presence of a slave drive. When the DRV bit is cleared, the master drive is selected, and when the DRV bit is set, the slave drive is selected. When drives are daisy chained, one must be set as the master and one as the slave. When a single drive is attached to the interface it must be set as the master. Throughout this document, drive selection always refers to the state of the DRV bit, and the position of the master/slave jumper. 5.1 I/O PORT ASSIGNMENTS Input and output to or from the drive is through an I/O port (see Table 5ú1) that routes the input or output data to or from fourteen registers (selected) by a code on the CS1FX-, CS3FX-, DA2, DA1, DA0, DIOR- and DIOW- lines from the host. Ten of the registers are used for commands to the drive or status, one is the data port and three are used for control and alternate status. These are referred to herein as the command block registers and the control block registers. Table 5ú2 lists these registers and the addresses that select them, together with the functions of addresses that do not select one of the registers. Logic conventions are 1 = signal asserted; 0 = signal negated; x = does not matter which it is. Table 5ú1 I/O Port Assignments Doc 1019708, Rev A 2 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual Table 5ú2 Selection Addresses and Functions 5.2 REGISTER DESCRIPTIONS The following paragraphs describe the operations of the registers listed in Table 5ú2. The error, precompensation, sector count, sector number, cylinder low, cylinder high, drive-head, and command register are accessible only when the BSY bit in the status register is cleared. 5.2.1 Data Register The data register is used to transfer the data during read and write operations. It is also used to transfer the sector table during the format commands. All data transfers are 16 bits wide except for the transfer of ECC bytes which are 8 bits wide. The transfer of ECC bytes only occurs during read or write long operations. The host can access the data register only when DRQ is set in the status register. 5.2.2 Error Register The error register contains status from the last command executed by the drive. The contents of this register are valid only when the error bit (ERR) is set in the status register, unless the drive has just powered up or completed execution of its internal diagnostic, in which case the register contains a status code (see section 5.2.9). The error bits in the register are defined in Table 5ú3. Table 5ú3 Error Bits in Register A bad block (BBK) bit of one indicates that a bad block mark was detected in the requested sector's ID field. An uncorrectable data (UNC) bit of one indicates that an uncorrectable data error has been encountered. Doc 1019708, Rev A 3 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual An ID not found (IDNF) bit of one indicates that the requested sector's ID field could not be found. An aborted command (ABRT) bit of one indicates that the requested command has been aborted due to a drive status error (not ready, write fault, etc.) or because the command code is invalid. A track 0 not found (TK0NF) bit of one indicates that track 0 has not been found during a RECALIBRATE command. An address mark not found (AMNF) bit of one indicates that the data address mark has not been found after finding the correct ID field. Reserved indicates that this bit is set to zero. Error bits set to zero indicate that no error was found. 5.2.3 Precompensation Register The precompensation register is used to enable or disable the Read Look-Ahead feature (see section 6.3.10). 5.2.4 Sector Count Register The sector count register defines the number of sectors of data to be read or written. If the value in this register is zero, a count of 256 sectors is specified. This count is decremented as each sector is read so the register contains the number of sectors left to access in the event of an error in a multisector operation. The contents of this register define the number of sectors per track when executing an INITIALIZE DRIVE PARAMETERS or FORMAT command. 5.2.5 Sector Number Register The sector number register contains the starting sector number for any disk access. At the completion of each sector, and at the end of the command, this register is updated to reflect the last sector read correctly, or the sector on which an error occurred. 5.2.6 Cylinder Low Register The cylinder low register contains the low order eight bits of the starting cylinder address for any disk access. At the completion of each sector, and at the end of the Doc 1019708, Rev A 4 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual command, this register is updated to reflect the current cylinder number. 5.2.7 Cylinder High Register The cylinder high register contains the high order bits of the starting cylinder address for any disk access. At the completion of each sector, and at the end of the command, this register is updated to reflect the current cylinder number. The most significant bits of the cylinder address should be loaded into the cylinder high register. 5.2.8 Drive-Head Register This register specifies the drive and head numbers. At the completion of each sector, and at the end of the command, this register is updated to reflect the currently selected head. See Table 5ú4, Drive-Head Register. Table 5ú4 Drive-Head Register It is recommended that the sector size bits be set to 01b to indicate the 512 byte sector size. However, these bits are ignored by the LXT-200A. The drive (DRV) bit is the binary encoded drive selected number. When this bit is cleared, the master drive is selected, and when this bit is set, the slave drive is selected. The head number field is the four bit binary encoded head select number. 5.2.9 Status Register The status register contains the drive status. The contents of this register are updated at the completion of each command. If the busy bit is asserted, no other bits are valid. The host reading this register when an interrupt is pending is considered to be the interrupt acknowledge, and any pending interrupt is therefore cleared whenever this register is read. The bits in this register are defined below in Table 5ú5. Doc 1019708, Rev A 5 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual Table 5ú5 Status Register Bits The busy (BSY) bit set whenever the drive has access to the command block registers, and the host is prevented from accessing the command block. This bit is set under the following circumstances: ú At assertion of the RESET- signal on the interface, or at setting of the SRST bit in the digital output register. ú Immediately upon host write of the command register with a READ, READ LONG, READ BUFFER SEEK, RECAL, INITIALIZE DRIVE PARAMETERS, VERIFY, IDENTIFY, or DIAGNOSTIC command. ú Immediately following transfer of 512 bytes of data during execution of a WRITE, FORMAT TRACK, or WRITE BUFFER command, or 512 bytes of data and the appropriate number of ECC bytes during the execution of a WRITE LONG command. When the BSY bit is set, any host read of a shared register is inhibited and the status register is read instead. When there is an error, the drive ready indication (DRDY) bit is not changed until the status register is read by the host, at which time the bit again indicates the current readiness of the drive. This bit should be cleared at power up and remain cleared until the drive is up to speed and ready to accept a command. When there is an error, the drive write fault (DWF) bit is not changed until the status register is read by the host, at which time the bit again indicates the current fault status. The drive seek complete (DSC) bit is always set after the drive is ready. When set, the data request (DRQ) bit indicates that the drive is ready for transfer of a word or byte of data between the host and the data port. The corrected data (CORR) bit, which is set when a correctable data error has been encountered and the data has been corrected. This condition does not terminate a multisector read operation. Doc 1019708, Rev A 6 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual The index (IDX) bit is set once per disk revolution. When set, the error (ERR) bit indicates that the previous command ended in error. The other bits in the status register, and the error register have additional information as to the cause of the error. 5.2.10 Command Register The eight bit code written to this register transfers to the drive the command that the host is requesting. Command execution begins immediately after this register is written. See chapter 6 for detailed information on the ATA command set. 5.2.11 Alternate Status Register The alternate status register contains the same information as the status register in the command block. The only difference is that reading this register does not imply interrupt acknowledge or clear a pending interrupt. See Table 5ú6, Alternate Status Register Bits. Table 5ú6 Alternate Status Register Bits See section 5.2.9 for definitions of the bits in this register. 5.2.12 Digital Output Register The digital output register contains two control bits. See Table 5ú7, Digital Register Bits. Table 5ú7 Digital Register Bits The drive is held reset when the host software reset (SRST) bit is set, and enabled when this bit is cleared. If two drives are daisy chained on the interface, this bit resets and enables both drives simultaneously. Doc 1019708, Rev A 7 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual The not interrupt enabled (NIEN) bit is the enable bit for the drive interrupt to the host. When this bit is set, and the drive is selected, the host interrupt, INTRQ, is enabled, through a tri-state buffer, to the host. When this bit is cleared, or the drive is not selected the INTRQ pin is in a high impedance state, regardless of the presence or absence of a pending interrupt. Bits in Table 5ú7 marked N/A are not used 5.2.13 Drive Address Register The drive address register loops back the drive select and head select addresses of the currently selected drive. The bits in this port are as described below in Table 5ú8. Table 5ú8 Drive Address Register Bits Bits marked N/A are undriven by the drive. When the host reads the drive address register, this bit is in a high impedance state. This is to prevent conflict with the floppy disk interface. The not write gate (NWTG) bit is cleared when writing to the drive is in progress. The head selected field is the one's complement of the binary coded address of the head number field. See table 5ú4, Drive-Head Register. The not drive select bit for drive 1 (NDS1) is cleared when drive 1 is selected and active. The not drive select bit for drive 0 (NDS0) is cleared when drive 0 is selected and active. NOTE: Use care interpreting these bits, as they do not always represent the expected status of drive operations at the instant the status was put into this register. This is because of the use of caching, translate mode and master/slave drives each having its own embedded controller. 5.3 RESET RESPONSE When the drive is reset, either by the host reset interface pin, RESET-, or by the SRST bit the drive sets BSY immediately. Once the reset has been removed and the Doc 1019708, Rev A 8 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual drive has been re-enabled, with BSY still set, the drive performs any necessary hardware initialization, clears any previously programmed drive parameters and reverts to the default condition, loads the command block registers with their initial values, and then clears BSY. No interrupt is generated when initialization is complete, and no self- test is performed. The initial values (hex) for the command block registers are shown in Table 5ú9. Table 5ú9 Initial Register Values Doc 1019708, Rev A 9 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual LXT-200A Product Specification & OEM Technical Manual Doc 1019708, Rev A 1 Maxtor Corporation Doc 1019708, Rev A 1 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 6.0 ATA COMMAND SET Commands are issued to the drive by loading the pertinent registers in the command block with the needed parameters, setting the not interrupt enable bit, NIEN in the digital output register, and then writing the command code to the command register. Execution begins as soon as the command register is written. A summary of commands and the re- quired parameters is given in Table 6ú1. Table 6ú1 Summary of Commands and Parameters Used If the long bit (L) is set to one, READ/WRITE LONG commands are executed. If the long bit is zero, normal READ/WRITE commands are performed. A retry (R) bit of zero enables retries. A retry bit of one disables retries. Retries are automatically re- enabled at the end of the command. PC is the write precompensation register. SC is the sector count register. SN is the sector number register. CY is the cylinder register. DH is the drive-head register Y means the register contains a valid parameter for this command. For the drive-head register, Y means that both the drive and head parameters are used. N means the register does not contain a valid parameter for this command. D means only the drive parameter is valid and not the head parameter. X means the value is not relevant. 6.1 ERROR REPORTING The errors that are valid for each command are defined in the matrix shown in Table 6ú2. Doc 1019708, Rev A 2 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual Table 6ú2 Valid Error Responses BBK is bad block detected. UNC is uncorrectable data error. IDNF is requested ID not found. ABRT is aborted command error TK0NF is track 0 not found error. AMNF is data address mark not found error. DRDY is disk drive not ready detected. DWF is disk drive write fault detected. DSC is disk drive seek complete not detected. CORR is corrected data error. ERR is the error bit in the status register. 6.2 TRANSLATE MODE The drive always operates in the translate mode because it uses zoned recording techniques. The drive firmware translates requests from the host into corresponding physical sector requests. Because the host communicates with the drive using physical drive parameters (i.e., cylinder number, head number, and sector number), a mapping address translation is needed to fully utilize the capacity of the drive. This also makes selecting a drive type from the BIOS tables easier. The drive type selected should have a capacity equal to or less than 201 megabytes. 6.3 COMMAND DESCRIPTIONS The drive implements the following standard commands: EXECUTE DRIVE DIAGNOSTIC FORMAT TRACK INITIALIZE PARAMETERS READ SECTOR(S) RECALIBRATE Doc 1019708, Rev A 3 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual SEEK VERIFY SECTOR(S) WRITE SECTOR(S) The drive implements the following extended commands: IDENTIFY DRIVE READ BUFFER READ MULTIPLE SET BUFFER MODE SET MULTIPLE WRITE BUFFER WRITE MULTIPLE 6.3.1 EXECUTE DRIVE DIAGNOSTIC Command The EXECUTE DRIVE DIAGNOSTIC command performs the internal diagnostic tests implemented by the drive. The diagnostic tests are executed only upon receipt of this command. They are not to be executed automatically at power up or after a reset. The drive sets BSY immediately upon receipt of the command. If the drive is a slave, the disk active/slave present signal is always asserted. The drive then performs the diagnostic tests and reports the results. If the drive is a master and a slave is connected, it waits up to 5 seconds for the slave to complete diagnostics, checks the state of the PDIAG signal and then reports the diagnostic results. If the drive is a master and a slave is not connected, it reports only its diagnostic results. Following this, the drive clears BSY, and generates an interrupt. The value in the error register should be viewed as an eight-bit code value and not as bit significant flags as described in section 5.2.2. Table 6ú3 defines the eight- bit code values and their meanings. Table 6ú3 Error Codes NOTE: If the slave drive fails diagnostics, the master drive "ORs" gates 80 hex with its own status and loads that code into the error register. If the slave drive passes diagnostics or there is no slave drive connected, the master drive "ORs" 00 with its own status and loads that code into the error register. Doc 1019708, Rev A 4 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 6.3.2 FORMAT TRACK Command The FORMAT TRACK command initializes the data fields to 00h for the virtual track. Because the drive uses a zoned bit recording technique, the physical track and the virtual track are not always the same. The drive is always operating in translation mode. As soon as the command register is written, the drive sets the DRQ bit in the status register and waits for the host to fill the buffer with 512 bytes of interleave table. Once all the data is transferred, the drive sets BSY and starts the command execution. At the completion of execution, the drive resets BSY and generates an interrupt. The interleave table is made up of two bytes per sector for the track. The host should fill the remaining bytes with 00. The first byte is the sector flag byte (fb). The second byte is the logical sector number (sn). See Table 6ú4, Interleave Table Example. Table 6ú4 Interleave Table Example The logical sector ranges from 1 to the maximum sector number specified in the sector count register. If a logical sector number is out of this range, or if any duplication occurs, the FORMAT TRACK command is aborted. The flag byte values are shown in Table 6ú5. Table 6ú5 Flag Byte Values An invalid flag causes the command to be aborted. In order to keep the drive sector reassignment scheme intact, the drive rejects commands when the interleave table has both 80h and 40h flags. That is, the FORMAT TRACK command cannot have mark bad and reassign sectors in the same track. Doc 1019708, Rev A 5 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 6.3.2.1 FORMAT SECTORS AS GOOD/BAD If the interleave consists of 00h and 80h or only 00h in the flag bytes, the controller reformats the ID field of every sector in that logical track, marks the sector ID either good or bad according to the interleave table. When the controller encounters a bad sector mark in the sector ID while reading or writing sectors, a bad sector flag detected error code (80h) will be posted and the command terminated. This will halt the streaming perfor- mance of the drive. Due to the cylinder/head skew, and the defect reassignment scheme employed in the drive, the logical sector is not mapped into a predictable physical sector location. The controller has to read the IDs for the whole track in order to figure out the physical offset to the index pulse. When formatting, the controller counts the sector pulse after the index to get to the right sector position and start the format operation. The data field of the logical sector is written with data pattern 00 after the format is done. The drive issues an interrupt to the host at the completion of this command. 6.3.2.2 REASSIGN BAD SECTORS If the interleave table consists of 00h and 40h, the controller executes a reassign block operation. For reassigning sectors, the controller uses the spare sector in the same physical track to relocate the sector. If a spare sector is not available, alternate sectors in the reserved alternate cylinder are used. Before reassigning the block, the data in the whole physical track is backed up in an alternate cylinder. After reassigning, the data is restored to the track. While backing up the track, any sector, other than the reassigned block or a known defect in the Plist or Glist, found to be bad will terminate the command with a SECTOR NOT FOUND error (error code 10h). The sector address is posted in the task file register. The host should re-is- sue the FORMAT TRACK command that includes the new bad sector in the interleave table. After backing up the data of the track, the track is reformatted with pre-defined interleave and headskew. The reassigned sector location is skipped, the following sectors are pushed to the next sector location. If no spare sector is available on the track, the remaining sectors are pushed to the spare cylinder area. Doc 1019708, Rev A 6 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual After the sector is reassigned, the defect sector locations are added to the drive Glist. After reassigning the block, the data in the reassigned block may be altered, but the data in all other blocks is preserved. The drive issues an interrupt to the host at the completion of this command. 6.3.3 IDENTIFY DRIVE Command The IDENTIFY DRIVE command enables the host to receive parameter information from the drive. When the command is issued, the drive sets BSY, stores the required parameter information in the sector buffer, sets the DRQ bit, and generates an interrupt. The host then reads the information out of the sector buffer. The parameter words in the buffer have the arrangement and meaning as shown in Table 6ú6, Format of Drive Parameters Information. All reserved bits or words should be zeroes. The data is transferred low byte first then high byte. Table 6ú6 Format of Drive Parameters Information The bits in the general configuration word are defined in Table 6ú7. Table 6ú7 General Configuration Bit Definitions 6.3.4 INITIALIZE DRIVE PARAMETERS Command The INITIALIZE DRIVE PARAMETERS command enables the host to control certain drive parameters. The drive uses 15 heads, 32 sectors, and 816 cylinders as its virtual configuration, but will accept any valid combination of parameters. If the configuration requested exceeds the capacity of the drive, an ABORTED COMMAND error is returned. Table 6ú8 enumerates the range of register values for this function. Doc 1019708, Rev A 7 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual Table 6ú8 INITIALIZE DRIVE PARAMETERS Register Values The Drive-Head value is checked. The Sector Count value is checked and if the value is not in the range of 1 to 63, an aborted command error is returned. The Cylinder value is not checked. 6.3.5 READ BUFFER Command The READ BUFFER command allows the host to read the current contents of the buffer. The number of sectors to be transferred is specified in the sector count register. If the number of sectors to be transferred exceeds the buffer size then an aborted command error is returned. A value of zero in the sector count register requests 256 sectors to be transferred; in which case one 512 byte transfer is allowed and an ABORTED COMMAND error is returned. When the command register is written, the drive sets the BSY bit, prepares the buffer, sets DRQ bit, clears the BSY bit, and generates an interrupt. The host then reads the data from the buffer. An interrupt is generated for each sector. 6.3.6 READ MULTIPLE Command The READ MULTIPLE command performs similarly to the READ SECTOR(S) command except that data transfers are in multiple sector blocks and the long bit is not valid. Command execution is identical to the READ SECTOR(S) operation but with several sectors transferred to the host as a block without intervening interrupts and requiring only DRQ qualification of the transfer at the start of the block, not on each sector. The block count, which is the number of sectors to be transferred as a block, is programmed by the SET MULTIPLE MODE command, which must be executed prior to the READ MULTIPLE command. When the read multiple command is issued, the sector count register contains the number of sectors (not the number of blocks or the block count) requested. If this sector count is not evenly divisible by the block count, as many full blocks as possible are transferred, followed by a final, partial block transfer. The partial block transfer will be for N sectors, where N = (sector count) modulo (block count). If the READ MULTIPLE command is attempted before the SET MULTIPLE MODE command has been executed or when READ Doc 1019708, Rev A 8 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual MULTIPLE commands are disabled, the READ MULTIPLE operation will be rejected with an ABORTED COMMAND error. Disk errors encountered during READ MULTIPLE commands are reported at the beginning of the block or partial block transfer, but DRQ is still set and the transfer will take place as it normally would, including transfer of corrupted data, if any. Subsequent blocks or partial blocks are transferred only if the error was a correctable data error. All other errors cause the command to stop after transfer of the block which contained the error. Interrupts are generated when DRQ is set at the beginning of each block or partial block. 6.3.7 READ SECTOR(S) Command The READ SECTOR(S) command reads from 1 to 256 sectors as specified in the command block (sector count equal to 0 requests 256 sectors), beginning at the specified sector. As soon as the command register is written, the drive sets the BSY bit and begins execution of the command. If the drive is not already on the desired track, a SEEK is per- formed to the desired track. The drive then searches for the appropriate ID field. If retries are disabled and two index pulses have occurred without error free reading of the requested ID, an ID NOT FOUND error is posted in the error register. If retries are enabled, up to a vendor specific number of attempts may be made to read the requested ID before reporting an error. If the ID is read correctly, the data address mark must be recognized within a specified number of bytes, or the data address mark not found error is reported. Once the data address mark is found, the data field is read into the sector buffer. Error bits are asserted if an error was encountered. The DRQ bit is set, and an in- terrupt is generated. The DRQ bit is always set, regardless of the presence or absence of an error condition at the end of the sector. Upon command completion, the command block registers contain the cylinder, head, and sector numbers of the last sector read. Multiple sector reads set DRQ and generate an interrupt when the sector buffer is filled at the completion of each sector. The drive is then ready for the data to be read by the host. DRQ is cleared and BSY is set immediately when the host empties the sector buffer. If an error occurs during a multiple sector read, the read terminates at the sector where the error occurred. The command block registers contain the cylinder, head, and sector numbers of the sector where the error occurred. The host may then Doc 1019708, Rev A 9 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual read the command block to determine what error has occurred, and on which sector. If the error was either a correctable data error or an uncorrectable data error, the flawed data is loaded into the sector buffer. A READ LONG command is executed by setting the long bit in the command code. The READ LONG command returns the data (512 bytes, 16 bit wide) and the ECC bytes (7 bytes, 8 bits wide) contained in the data field of the desired sector. During a READ LONG command, the drive does not check the ECC bytes to determine if there has been any type of data error. Only single sector READ LONG operations are supported. 6.3.8 RECALIBRATE Command The RECALIBRATE command moves the read-write heads from anywhere on the disk to cylinder zero. Upon receipt of the command, the drive sets BSY and issues a SEEK command to cylinder zero. The drive then waits for the SEEK to complete before updating status, clearing BSY and generating an interrupt. If the drive cannot reach cylinder zero, the error bit is set in the status register, and the track zero bit set in the error register. 6.3.9 SEEK Command The SEEK command initiates a seek to the track and selects the head specified in the command block. The drive need not be formatted for a SEEK to execute properly. When the command is issued, the drive sets BSY in the status register, initiates the SEEK, clears BSY, and generates an interrupt. The SEEK is not completed before the drive returns the interrupt. The drive SEEK complete bit is not toggled. If a new command is issued to a drive while a SEEK is being executed, the drive delays with BSY set for the SEEK to complete before executing the new command. If the cylinder is not valid, the SEEK is not performed. The SEEK complete bit is set, and a command abort error is reported. 6.3.10 SET BUFFER MODE Command The SET BUFFER MODE command enables or disables the Read look-ahead feature. Prior to command issuance, the write precompensation register should be loaded with either AAh to enable, or 55h to disable read look-ahead operation. Upon receipt of the command, the controller asserts and checks at the write precompensation register contents. If Doc 1019708, Rev A 10 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual the register contents are either 55h or AAh, the appropriate mode is selected. Any other value in the register results in an aborted command. At command completion, the controller clears BSY and generates an interrupt. At power up, or after a software or hardware reset, the default mode is read look-ahead enabled. 6.3.11 SET MULTIPLE MODE Command The SET MULTIPLE MODE command enables the drive to perform READ and WRITE MULTIPLE operations and establishes the block count for these commands. Prior to command issuance, the sector count register should be loaded with the number of sectors per block. The drive supports block sizes of 1, 2, 4, 8, 16, and 32 sectors, to maintain 1:1 performance. Upon receipt of the command, the controller sets BSY and checks the sector count register contents. If the register contents are a valid and the block count is supported, the value is loaded for all subsequent READ and WRITE MULTIPLE commands and execution of those commands is enabled. Any unsupported block count in the register results in an ABORTED COMMAND error and READ and WRITE MULTIPLE commands being disabled. If the sector count register contains 0 when the command is issued, READ and WRITE MULTIPLE commands are disabled. Once the appropriate action has been taken, the controller clears BSY and generates an interrupt. At power up, or after a hardware or software reset, the default mode is read and write multiple disabled. 6.3.12 VERIFY SECTOR(S) Command The VERIFY SECTOR(S) command is identical to the READ SECTOR(S) command, except that DRQ is never set. No data is transferred to the host and the long bit is not valid. The drive sets BSY as soon as the command register is written and then clears BSY and generates an interrupt when the requested sectors have been verified. Upon command completion, the command block registers contain the cylinder, head, and sector number of the last sector verified. If an error occurs during a multiple sector verify, the read terminates at the sector where the error occurs. The command block registers contain the cylinder, head, and sector number of the sector where the error occurred. Doc 1019708, Rev A 11 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 6.3.13 WRITE BUFFER Command The WRITE BUFFER command enables the host to write to the buffer. The number of sectors to be transferred is specified in the sector count register. If the number of sectors to be transferred exceeds the buffer size, an ABORTED COMMAND error is returned. A value of zero in the sector count register requests 256 sectors to be transferred; in which case one 512 byte transfer is allowed and an ABORTED COMMAND error is returned. When this command register is written, the drive sets the BSY bit, prepares the buffer, sets the DRQ bit, clears the BSY bit, and generates an interrupt. The host then writes the data to the buffer. An interrupt is generated for each sector. 6.3.14 WRITE MULTIPLE Command The WRITE MULTIPLE command performs similarly to the WRITE SECTOR(S) command except that the controller sets BSY immediately upon receipt of the command. Data transfers are multiple sector blocks, and the long bit is not valid. Command execution is identical to the write sector(s) operation, but with several sectors transferred by the host as a block without intervening interrupts and only requiring DRQ qualification of the transfer at the start of the block, not on each sector. The block count, which is the number of sectors to be transferred, is programmed by the SET MULTIPLE MODE command, which must be executed prior to the WRITE MULTIPLE command. When the WRITE MULTIPLE command is issued, the sector count register contains the number of sectors (not the number of blocks or the block count) requested. If this sector count is not evenly divisible by the block count, as many full blocks as possible are transferred, followed by a final, partial block transfer. The partial block transfer is for N sectors, where N = (sector count) modulo (block count). If the WRITE MULTIPLE command is attempted before the SET MULTIPLE MODE command has been executed or when WRITE MULTIPLE commands are disabled, the WRITE MULTIPLE operation is rejected with an ABORTED COMMAND error. All disk errors encountered during WRITE MULTIPLE commands are reported after the attempted disk write of the block or partial block transferred. The write operation ends with the sector in error, even if it was in the middle of a block. Subsequent blocks are not transferred in the event of an error. Interrupts are generated when DRQ is set at the beginning of each block or partial block. Doc 1019708, Rev A 12 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual 6.3.15 WRITE SECTOR(S) Command The WRITE SECTOR(S) command writes from 1 to 256 sectors as specified in the command block (sector count equal to 0 requests 256 sectors), beginning at the specified sector. As soon as the command register is written, the drive sets the DRQ bit and waits for the host to fill the buffer with the data to be written. An interrupt is not generated to start the first 512 byte data transfer operation; however, an interrupt is generated for each successive 512 byte transfer until the buffer is full, the sector count is exhausted, or an error occurs. If the drive is not already on the desired track, a SEEK is performed to the desired track. The drive then searches for the appropriate ID field. If retries are disabled and two index pulses have occurred without an error free reading of the requested ID, an ID NOT FOUND error is posted in the error register. If retries are enabled, a specific number of attempts are made to read the requested ID before reporting an error. If the ID is read correctly, the data loaded in the buffer is written to the data field of the sector, followed by the ECC bytes. Upon command completion, the command block registers contain the cylinder, head, and sector number of the last sector written. Multiple sector writes set DRQ and generate an interrupt each time the buffer is ready to be filled. DRQ is cleared and BSY is set immediately when the host fills the sector buffer. If an error occurs during a multiple sector write, writing terminates at the sector where the error occurs. The command block registers contain the cylinder, head, and sector number of the sector where the error occurred. The host may then read the command block to determine which error has occurred, and on which sector. A WRITE LONG is executed by setting the long bit in the command code. The WRITE LONG command writes the data (512 bytes, 16 bit wide) and the ECC bytes (7 bytes, 8 bits wide) directly from the sector buffer. The drive does not generate the ECC bytes itself. Only single sector WRITE LONG operations are supported. Doc 1019708, Rev A 13 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual LXT-200A Product Specification & OEM Technical Manual Doc 1019708, Rev A 63 Maxtor Corporation Doc 1019708, Rev A 63 Maxtor Corporation LXT-200A Product Specification & OEM Technical Manual APPENDIX A: CDB BIT DEFINITIONS Abbreviation Meaning ABRT aborted command bit AMNF address mark not found bit BBK bad block bit BSY busy bit CORR corrected data bit DRDY drive ready indication bit DRQ data request bit DRV master or slave drive select bit DSC drive seek complete bit DWF drive write fault bit ERR error bit IDNF ID not found bit IDX index bit L long bit NDS0 not drive select bit for 0 NDS1 not drive select bit for 1 NIEN not interrupt enable bit NWTG not write gate bit R retry bit SRST host software reset bit TK0NF track 0 not found bit UNC uncorrectable data bit Doc 1019708, Rev A 64 Maxtor Corporation APPENDIX B: UNITS OF MEASURE Abbreviation Meaning A/m amps per meter AWG American wire gauge bpi bits per inch dBa decibel, A-weighted fci flux changes per inch g gram Gbyte gigabyte Hz hertz mA milliamp æA microamp Mbit megabit Mbyte megabyte æm micrometer msec millisecond æsec microsecond nsec nanosecond Oe oersted RH relative humidity rpm revolutions per minute tpi tracks per inch xxb binary values xxh hexadecimal values Doc 1019708, Rev A 68 Maxtor Corporation Doc 1019708, Rev A 68 Maxtor Corporation GLOSSARY assert. A signal driven to the true state. async. Asynchronous bit. Binary digit byte. Eight consecutive binary digits clear. A bit has a value of zero. connect. The function that occurs when an initiator selects a target to start an operation. CRC. Cyclic redundancy check CSA. Canadian Standards Association DC. Direct current DMA. Direct memory access ECC. Error correction code EIA. Electrical Industry Association EPROM. Erasable programmable read only memory FCC. Federal Communication Commission FIFO. First-in, first-out storage and retrieval technique firmware. Computer programs encoded permanently into a ROM G. Constant of gravitation gnd. Ground hard error. An error due to faulty equipment, transmission techniques, recording media, etc. HDA. Head disk assembly hex. Hexadecimal I/O. Input and/or output ISG. Inter-sector gap ISO. International Standardization Organization LBA. Logical block address Doc 1019708, Rev A 69 Maxtor Corporation LED. Light-emitting diode logical thread. The logical path which exists between an initiator's memory and a bus device LUN, even though the physical path may be disconnected. logical unit. A physical or virtual device addressable through a target. LSB. Least significant byte LSTTL. Low power, Schotky transistor-transistor logic LUN. Logical unit number, an encoded 3-bit identifier for the logical unit. æC. Microcomputer æcomputer. Microcomputer MFM. Modified frequency modulation (encoding) MTBF. Mean time between failures MTTR. Mean time to repair N.C. No connection negate. A signal driven to the false state nom. Nominal OEM. Original equipment manufacturer one. True signal value parity. A method of checking the accuracy of binary numbers PCB. Printed circuit board PLL. Phase-locked loop PLO. Phase-locked oscillator P/N. Part number POH. Power On hours P-P. Peak to peak PROM. Programmable read only memory RAM. Random-access memory Doc 1019708, Rev A 70 Maxtor Corporation reconnect. The function that occurs when a target selects an initiator to continue an operation after disconnect. release. The act of allowing the cable terminators to bias the signal to the false state (by placing the driver in the high impedance condition). req. Request reserved. Bits, bytes, fields and code values that are set aside for future standardization. RLL. Run-length limited ROM. Read-only memory R/W. Read and/or write set. A bit has a value of one. TLA. Top level assembly TTL. Transistor-transistor logic typ. Typical UL. Underwriter's Laboratories, Inc. UNC. Unified National Coarse UNF. Unified National Fine VDE. Verband Deutscher Electrotechniker zero. False signal code Doc 1019708, Rev A 71 Maxtor Corporation