5.5 Ultra DMA Feature Set

5.5 Ultra DMA Feature Set

5.5.1 Overview

Ultra DMA is a data transfer protocol used with the READ DMA and WRITE DMA commands. When this protocol is enabled it shall be used instead of the Multiword DMA protocol when these commands are issued by the host. This protocol applies to the Ultra DMA data burst only. When this protocol is used there are no changes to other elements of the ATA protocol (e.g.: Command Block Register access).

Several signal lines are redefined to provide new functions during an Ultra DMA burst. These lines assume these definitions when 1) an Ultra DMA Mode is selected, and 2) a host issues a READ DMA or a WRITE DMA, command requiring data transfer, and 3) the host asserts DMACK-. These signal lines revert back to the definitions used for non-Ultra DMA transfers upon the negation of DMACK- by the host at the termination of an Ultra DMA burst. All of the control signals are unidirectional. DMARQ and DMACK- retain their standard definitions.

With the Ultra DMA protocol, the control signal (STROBE) that latches data from

DD(15:0) is generated by the same agent (either host or device) that drives the data onto the bus. Ownership of DD (15:0) and this data strobe signal are given either to the device during an Ultra DMA data in burst or to the host for an Ultra DMA data out burst.

During an Ultra DMA burst a sender shall always drive data onto the bus, and after a sufficient time to allow for propagation delay, cable settling, and setup time, the sender shall generate a STROBE edge to latch the data. Both edges of STROBE are used for data transfers so that the frequency of STROBE is limited to the same frequency as the data.

Words in the IDENTIFY DEVICE data indicate support of the Ultra DMA feature and the Ultra DMA Modes the device is capable of supporting. The Set transfer mode subcommand in the SET FEATURES command shall be used by a host to select the Ultra DMA Mode at which the system operates. The Ultra DMA Mode selected by a host shall be less than or equal to the fastest mode of which the device is capable. Only the Ultra DMA Mode shall be selected at any given time. All timing requirements for a selected Ultra DMA Mode shall be satisfied. Devices supporting Ultra DMA Mode 2 shall also support Ultra DMA Modes 0 and 1. Devices supporting Ultra DMA Mode 1 shall also support Ultra DMA Mode 0.

An Ultra DMA capable device shall retain its previously selected Ultra DMA Mode after executing a Software reset sequence. An Ultra DMA capable device shall clear any previously selected Ultra DMA Mode and revert to its default non- Ultra DMA Modes after executing a Power on or hardware reset.

C141-E221

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Fujitsu MHV2080AS, MHV2060AS, MHV2040AS manual Ultra DMA Feature Set, Overview
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MHV2060AS, MHV2080AS, MHV2040AS specifications

Fujitsu's MHV series of hard disk drives, specifically the MHV2040AS, MHV2080AS, and MHV2060AS models, are designed to deliver efficient performance and reliability for a range of applications, particularly in desktop computing and entry-level servers. Each of these drives adheres to the Serial ATA (SATA) interface, which ensures compatibility across a wide range of systems and is known for its cost-effectiveness and simplicity.

The MHV2040AS features a storage capacity of 40GB, making it suitable for basic computing tasks including document editing, web browsing, and media playback. The MHV2060AS steps it up with a 60GB capacity, allowing for increased data storage needs while still maintaining a high level of performance. The largest of the trio, the MHV2080AS, offers an impressive 80GB of space, positioning it well for users who require additional room for applications, games, and multimedia files.

All drives in this series are equipped with a rotational speed of 5400 RPM, which strikes a balance between speed and power consumption. This speed is adequate for everyday tasks and allows for quick boot times and file access, making them ideal for home and small office environments. Additionally, the drives feature an average latency of 5.5 milliseconds, contributing to their overall performance in retrieving data.

In terms of technology, the MHV series employs a fluid dynamic bearing (FDB) motor, which not only enhances reliability but also reduces noise levels during operation. The FDB technology helps improve the longevity of the drives by minimizing wear on mechanical components. This characteristic is particularly important for users seeking quieter drives, especially in work environments that require minimal disruption.

The drives also incorporate advanced power management features that significantly reduce power consumption, making them an environmentally friendly choice for users mindful of their carbon footprint. These drives are equipped with energy-saving modes that optimize their performance when not in full use, ensuring lower operational costs and longer lifespan.

Overall, the Fujitsu MHV2040AS, MHV2080AS, and MHV2060AS hard drives provide a solid solution for users looking for dependable storage with a range of capacities to fit their needs. Their performance, combined with noise reduction technologies and energy efficiency, makes them a notable choice for various computing environments, from single-user desktops to small business applications.
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