INTERFACECOMMANDS

Read DMA

Multi-word DMA

Identical to the Read Sector(s) command, except that

1.The host initializes a slave-DMA channel prior to issuing the command,

2.Data transfers are qualified by DMARQ and are performed by the slave-DMA channel and

3.The drive issues only one interrupt per command to indicate that data transfer has terminated and status is available.

Ultra DMA

With the Ultra DMA Read protocol, the control signal (DSTROBE) that latches data from DD(15:0) is generated by the devices which drives the data onto the bus. Ownership of DD(15:0) and this data strobe signal are given DSTROBE to the drive during an Ultra DMA data in burst.

During an Ultra DMA Read burst, the drive always moves data onto the bus, and, after a sufficient time to allow for propagation delay, cable settling, and setup time, the sender shall generate a DSTROBE edge to latch the data. Both edges of DSTROBE are used for data transfers.

Any unrecoverable error encountered during execution of a Read DMA command terminates data transfer after the transfer of all sectors prior to the sector where the error was detected. The sector in error is not transferred. The drive generates an interrupt to indicate that data transfer has terminated and status is available. The error posting is identical to the Read Sector(s) command.

Read Multiple

Performs similarly to the Read Sector(s) command, except that for each READ MULTIPLE command data transfers are multiple sector blocks and the Long bit is not valid.

Execution is also similar to that of the READ SECTOR(S) command, except that:

1.Several sectors are transferred to the host as a block, without intervening interrupts.

2.DRQ qualification of the transfer is required only at the start of each block, not of each sector.

The block count consists of the number of sectors to be transferred as a block. (The block count is programmed by the Set Multiple Mode command, which must be executed prior to the Read Multiple command.) READ LONG command is limited to single sector requests.

When the Read Multiple command is issued, the Sector Count register contains the number of sectors requested — not the number of blocks or the block count. If the number of sectors is not evenly divisible by the block count, as many full blocks as possible are transferred, followed by a final, partial block transfer. This final, partial block transfer is for N sectors, where N = (sector count) modulo (block count)

The Read Multiple operation will be rejected with an Aborted Command error if attempted:

1.Before the Set Multiple Mode command has been executed, or

2.When Read Multiple commands are disabled.

The controller reports disk errors encountered during Read Multiple commands at the start of the block or partial block transfer. However, DRQ still sets, and the transfer occurs normally, along with the transfer of any corrupt data. Remaining block data from the following the sector in error is not valid.

If the Sector Count register contains 0 when the Set Multiple Mode command is issued, Read Multiple and Write Multiple commands are disabled; no error is returned. Once the appropriate action has been taken, the controller resets BSY and generates an interrupt. At power up, or after a hardware or software reset, Read Multiple and Write Multiple commands are disabled by default.

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Maxtor 91366U4, 91024U3, 90683U2, 92049U6, 91707U5, 92732U8 manual Read DMA, Read Multiple

91024U3, 92049U6, 90683U2, 91707U5, 92732U8 specifications

The Maxtor series of hard drives, specifically the models 91366U4, 92732U8, 91707U5, 90683U2, and 92049U6, exemplify the evolution of storage technology during the late 1990s and early 2000s, pivotal in shaping contemporary data storage solutions. These hard drives are recognized for their reliability, performance, and impressive capacities for their time.

The Maxtor 91366U4 features a storage capacity of 13.6 GB, delivering a spindle speed of 5,400 RPM. Its UATA interface allows for a fast data transfer rate, which was notable in its category. The model incorporates Advanced Power Management, contributing to lower power consumption and reduced heat generation, making it an appealing choice for system builders looking to enhance system longevity.

Moving on to the Maxtor 92732U8, this model increased capacity to 27.3 GB, aligning with the growing demand for more storage from users and businesses alike. This drive maintained a 5,400 RPM spindle speed while improving the access times, which aided in speeding up file retrieval processes. Noteworthy is its Plug and Play capability, which simplified installation and compatibility across various systems.

The Maxtor 91707U5 brought forward advancements in data integrity with the inclusion of features such as error correction codes. With a storage size of 17.3 GB and similar operational speeds, this model catered to users seeking reliable data management. Its robust build aimed to protect against accidents and environmental factors, ensuring data was safe while providing consistent performance.

The Maxtor 90683U2, with its 68.3 GB capacity, is particularly recognized for its reliability in desktop applications. The drive integrates a combination of Unidirectional Technology, driving advancements in read/write capabilities, and extensive shock protection, making it an ideal candidate for users with intensive data processing requirements.

Lastly, the Maxtor 92049U6 is known for its balanced blend of performance and functionality. Holding a capacity of 49.1 GB and retaining the sophisticated features of its predecessors, this model enabled faster data access and storage capabilities that met the needs of both home and professional users.

Together, these Maxtor hard drives embody the technological strides in the evolution of data storage—offering capacities and performances that set a standard in the industry and laid the groundwork for future storage solutions. The combination of innovative technologies and practical features made these drives highly sought after during their respective periods, and their legacy continues to influence modern data storage products.