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-E217

5-137

Page 213
Image 213
Fujitsu MHV2060AH, MHV2100AH, MHV2080AH, MHV2040AH manual Ultra DMA Feature Set, Overview

MHV2040AH, MHV2080AH, MHV2060AH, MHV2100AH specifications

The Fujitsu MHV series of hard disk drives, specifically the MHV2060AH, MHV2080AH, MHV2100AH, and MHV2040AH, are renowned for their reliability and performance in the mobile HDD segment. Designed primarily for use in laptops and other portable devices, these drives integrate cutting-edge technologies to meet the demands of today's data-intensive applications.

One of the hallmark features of the MHV series is its high data density, allowing for substantial storage capabilities in compact sizes. The MHV2060AH offers a storage capacity of 60 GB, while the MHV2080AH and MHV2100AH offer 80 GB and 100 GB respectively. The MHV2040AH provides a slightly more modest but still robust 40 GB of storage. This range of capacities ensures that users can select the model that best fits their storage needs.

The drives utilize the latest perpendicular magnetic recording (PMR) technology, which enhances recording efficiency and increases data storage densities. This technology significantly optimizes the use of disk surface area, providing better performance and more reliable data access. Additionally, the MHV series incorporates an advanced actuator system that ensures precision head positioning, enhancing data integrity and reducing error rates during read and write operations.

In terms of performance, the MHV series maintains a revolutions per minute (RPM) rating of 5400, which strikes a balance between speed and energy efficiency, making these drives suitable for low-power applications. The drives are also designed with a low acoustic level, generating minimal noise during operation—a crucial factor for mobile users who prefer quieter devices.

Furthermore, the Fujitsu MHV series features a robust shock resistance design, allowing them to withstand the rigors of mobile computing. This makes them suitable for use in portable environments subject to vibration and physical movement, thus ensuring data security and drive longevity.

Overall, the Fujitsu MHV2060AH, MHV2080AH, MHV2100AH, and MHV2040AH represent a formidable selection of mobile hard disk drives filled with advanced technologies and features, making them well-suited for a wide range of applications in today's fast-paced digital world. With their combination of storage capacity, performance, and durability, these drives continue to serve as reliable solutions for users seeking efficient data storage in portable formats.