Manuals / Fujitsu / Computer Equipment / Computer Drive

Fujitsu MHV2040AH, MHV2100AH, MHV2060AH, MHV2080AH manual Ultra DMA CRC rules

Models: MHV2040AH MHV2080AH MHV2060AH MHV2100AH

1 280
Download 280 pages 2.14 Kb
Page 223
Image 223

5.5 Ultra DMA Feature Set

13)The host shall neither negate STOP nor HSTROBE until at least tACK after negating DMACK-.

14)The host shall not assert DIOW-, CS0-, CS1-, DA2, DA1, or DA0 until at least tACK after negating DMACK.

5.5.5Ultra DMA CRC rules

The following is a list of rules for calculating CRC, determining if a CRC error has occurred during an Ultra DMA burst, and reporting any error that occurs at the end of a command.

a)Both the host and the device shall have a 16-bit CRC calculation function.

b)Both the host and the device shall calculate a CRC value for each Ultra DMA burst.

c)The CRC function in the host and the device shall be initialized with a seed of 4ABAh at the beginning of an Ultra DMA burst before any data is transferred.

d)For each STROBE transition used for data transfer, both the host and the device shall calculate a new CRC value by applying the CRC polynomial to the current value of their individual CRC functions and the word being transferred. CRC is not calculated for the return of STROBE to the asserted state after the Ultra DMA burst termination request has been acknowledged.

e)At the end of any Ultra DMA burst the host shall send the results of its CRC calculation function to the device on DD (15:0) with the negation of DMACK-.

f)The device shall then compare the CRC data from the host with the calculated value in its own CRC calculation function. If the two values do not match, the device shall save the error and report it at the end of the command. A subsequent Ultra DMA burst for the same command that does not have a CRC error shall not clear an error saved from a previous Ultra DMa burst in the same command. If a miscompare error occurs during one or more Ultra DMA bursts for any one command, at the end of the command, the device shall report the first error that occurred.

g)For READ DMA or WRITE DMA commands: When a CRC error is detected, it shall be reported by setting both ICRC and ABRT (bit 7 and bit 2 in the Error register) to one. ICRC is defined as the "Interface CRC Error" bit. The host shall respond to this error by re-issuing the command.

h)A host may send extra data words on the last Ultra DMA burst of a data out command. If a device determines that all data has been transferred for a command, the device shall terminate the burst. A device may have already received more data words than were required for the command. These extra words are used by both the host and the device to calculate the CRC, but, on an Ultra DMA data out burst, the extra words shall be discarded by the device.

C141-E217

5-147

Page 222 Page 224
Page 223
Image 223
Fujitsu MHV2040AH, MHV2100AH, MHV2060AH, MHV2080AH manual Ultra DMA CRC rules
Page 222 Page 224

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.