Samsung M8-DVR manual Firmware Features, Write Channel, Read Caching

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5.4.2The Write Channel

The signal path for the Write Channel follows the reverse order of that for the Read Channel. The host transmits data via the AT bus to the 88i9422 Interface Controller. The Buffer Controller section of the 88i9422 stores the data in the cache. Because the data is transmitted to the drive at a rate that exceeds the rate at which the drive can write data to the disk, data is stored temporarily in the cache. Thus, the host can present data to the drive at a rate independent of the rate at which the drive can write data to the disk.

Upon correct identification of the target address, the data is shifted to the Sequencer, which generates and appends an error correcting code. The Sequencer then converts the bytes of data to a serial bit stream. The AT controller also generates a preamble field, inserts an address mark, and transmits the data to the ENDEC in the R/W IC where the data is encoded into the LDPC format and pre-compensates for non-linear transition shift. The amount of write current is set by the 88i9422 DSP and Interface/Disk Controller through the serial interface to the preamplifier.

The 88i9422 switches the Preamplifier and Write Driver IC to write mode and selects a head. Once the Preamplifier and Write Driver IC receive a write gate signal, it transmits current reversals to the head, which writes magnetic transitions on the disk.

5.5 Firmware Features

This section describes the following firmware features:

Read Caching

Write Caching

Track Skewing

Defect Management

Automatic Defect Allocation

ECC Correction

SMART (Self-monitoring and reporting technology)

ATA security mode features

ATA host protected area

ATA streaming features

ATA power up in stand by feature set

ATA advanced power management (APM) feature set

ATA device configuration overlay (DCO) feature set

5.5.1Read Caching

The Spinpoint M8 hard disk drive uses Read Cache to enhance drive performance and significantly improve system throughput. Use the SET FEATURES command to enable or disable Read Caching. Read caching anticipates host-system requests for data and stores that data for faster future access. When the host requests a certain segment of data, the cache feature utilizes a prefetch strategy to get the data in advance and automatically read and store the following data from the disk into fast RAM. If the host requests this data, the RAM is accessed rather than the disk.

There is a high probability that subsequent data requested will be in the cache, because more than 50 percent of all disk requests are sequential. It takes microseconds rather than milliseconds to retrieve this cached data. Thus Read Caching can provide substantial time savings during at least half of all disk requests. For example, Read Caching

Spinpoint M8-DVR Disti Product Manual REV 2.0

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Contents M8-DVR Product Manual Page Table of Contents Smart APM Read Fpdma Queued 60h Read Log Extended 2Fh Read Long 22h Table of Tables Manual Organization ScopeUser Definition Sata ReferenceDescription IntroductionKey Features Standards and Regulations Hardware RequirementsSpecifications Specification SummaryPhysical Specifications Physical SpecificationsLogical Configurations Physical dimensionsPerformance Specifications Power Requirements Power consumptionPower consumption RatedLinear Shock 1/2 sine pulse Environmental SpecificationsEnvironmental Specifications Rotational Shock1Measurement Position Reliability Specifications Annualized Failure Rate AFRInstallation Space RequirementsUnpacking Instructions MountingMounting Dimensions OrientationSata Connectivity Cable ConnectorsVentilation Computer mainboard Serial ATA Power ManagementSATA-Bus Interface Connector HDD Power, Sata Interface, and Factory Jumper ConnectorPin Locations on the Drive Pcba Drive Installation DC Power Connector and SATA-Bus Interface Cable ConnectionsDC Spindle Motor Assembly Head / Disk Assembly HDABase Casting Assembly Disk Drive OperationCoverAssembly Voice Coil Motor and Actuator Latch Assemblies Disk Stack AssemblyHead Stack Assembly Air Filtration SystemDisk Controller Digital Signal Process and Interface ControllerDrive Electronics DDR Host Interface Control Block Buffer Control BlockFrequency Synthesizer Disk Control BlockDisk Ldpc Control Block Time Base Generator Power ManagementRead/Write IC Automatic Gain ControlAnalog Anti-Aliasing Low Pass Filter Analog to Digital Converter ADC and FIRRead Channel Servo SystemRead and Write Operations Read Caching Firmware FeaturesWrite Channel Write Caching Smart Defect ManagementAutomatic Defect Allocation 6 APMSata II Interface Sata TerminologySpinpoint M8-DVR Disti Product Manual REV Physical Interface Signal Summary Signal DescriptionsControl Block Register Descriptions When read When written2 I/O Register Address RegistersCommand Block Register Descriptions Command Register Ex F7h Device Register Ex F6hStatus Register Ex F7h Staggered Spin-up Disable Control Sata II Feature SETDevice Activity Signal Auto-Activate in DMA Setup FISPhy. Event Counters Software Settings Preservation Sata Power ManagementCommand Code Parameters ATA Command DescriptionsCommand Table Smart Device Configuration Overlay B1h Command DescriptionsCheck Power Mode E5h Download Micro Code 92hDevice Configuration Identify data structure Word Content Flush Cache E7h, EAh extended Execute Device Diagnostics 90hDiagnostic Codes Format Track 50hContent Description Identify Device information=the fields reported in word 88 are valid EXT =Media Card Pass Through command feature set supported Word Content Description WWNIdle Immediate E1h Automatic Standby Timer PeriodsIdle E3h Read Buffer E4h Initialize Device Parameters 91hNOP 00h Read DMA C8h, 25h extendedRead Long 22h Read Multiple Command C4h, 29h extendedRead Log Extended 2Fh Read Verify Sectors 40h, 41h extended Read Native Max Address F8h, 27h extendedRead Sectors 20h, 24h extended Security Erase Prepare F3h Security Disable Password F6hRecalibrate 10h Security Erase Unit F4hSecurity Set Password data content Security Set Password F1hSecurity Erase Unit Password Security Freeze Lock F5hSecurity Unlock F2h Set Features EFhIdentifier Level Command result Seek 7xh11 Set Features Register Definitions 12 Transfer Mode ValuesSet Max Address F9h, 37h extended Set Multiple Mode C6h13 Set Max Feature Register Values Sleep E6hSmart enable/disable attribute auto-save D2h 14 Smart Feature Registers ValuesSmart disable operations D9h Smart B0hSmart enable operations D8h Smart execute off-line immediate D4hSmart read data D0h 15 Device Smart Data StructureByte Bit Name Description 16 Smart Attribute Status Flags17 Smart Attribute Data List 18 Off-line Data Collection Status ValuesSelf-test execution status byte 19 Self-test Execution Status ValuesSmart write log sector D6h Smart read log sector D5hSmart return status DAh Write DMA CAh, 35h extended Standby Immediate E0hWrite Buffer E8h Write Fpdma Queued 61hWrite Sectors 30h, 34h extended Write Multiple Command C5h, 39h extendedWrite Long 32h Spinpoint M8-DVR Disti Product Manual REV General Information MaintenanceMaintenance Precautions HDD handling guide -Please handle HDD by side surfaces Service and Repair HDD handling guide Prevent Shocks

M8-DVR specifications

The Samsung M8-DVR is an advanced digital video recorder designed to meet the ever-evolving demands of modern surveillance and recording needs. This cutting-edge device combines state-of-the-art technology with user-friendly features, making it a reliable choice for both residential and commercial applications.

At the core of the M8-DVR’s design is its high-definition recording capability. The device supports various resolutions, including Full HD 1080p, ensuring that all captured footage is crystal clear. This clarity is crucial for identifying details, whether for security purposes or monitoring activities around the clock. It can accommodate multiple camera inputs, allowing users to expand their surveillance network seamlessly.

One of the standout features of the M8-DVR is its remarkable storage capacity. Equipped with advanced hard disk technology, it can store several terabytes of footage, which can be further expanded using additional drives. This means that even with continuous recording, users won’t have to worry about running out of storage quickly. The device also incorporates efficient compression technologies, such as H.265, which allows for reduced file sizes without sacrificing video quality.

In terms of connectivity, the M8-DVR offers various options, including Ethernet ports for network connectivity, USB ports for data transfer, and HDMI output for direct connection to monitors. This versatility allows users to easily stream live footage or review recordings on larger screens. The device supports remote viewing through mobile applications, allowing users to monitor their property from virtually anywhere in real-time.

User experience is further enhanced by an intuitive interface that makes navigation simple and efficient. It includes features like motion detection and alerts, which notify users of any unusual activities. The advanced search function is another highlight, enabling users to quickly locate specific events in their recordings without long hours of scrolling.

The Samsung M8-DVR is also designed with durability in mind. It comes with robust security features to protect against unauthorized access and offers backup options to prevent data loss. With its blend of technology, storage capabilities, and user-friendly design, the Samsung M8-DVR stands out as a comprehensive solution for modern video surveillance needs, making it an essential tool for enhancing security and peace of mind in any environment.