5.4Command Protocol

The host should confirm that the BSY bit of the Status register of the device is 0 prior to issue a command. If BSY bit is 1, the host should wait for issuing a command until BSY bit is cleared to 0.

Commands can be executed only when the DRDY bit of the Status register is 1. However, the following commands can be executed even if DRDY bit is 0.

∙EXECUTE DEVICE DIAGNOSTIC

∙INITIALIZE DEVICE PARAMETERS

5.4.1Data transferring commands from device to host

The execution of the following commands involves data transfer from the device to the host.

∙IDENTIFY DEVICE

∙IDENTIFY DEVICE DMA

∙READ SECTOR(S)

∙READ LONG

∙READ BUFFER

∙SMART: SMART Read Attribute Values, SMART Read Attribute Thresholds

The execution of these commands includes the transfer one or more sectors of data from the device to the host. In the READ LONG command, 516 bytes are transferred. Following shows the protocol outline.

a)The host writes any required parameters to the Features, Sector Count, Sector Number, Cylinder, and Device/Head registers.

b)The host writes a command code to the Command register.

c)The device sets the BSY bit of the Status register and prepares for data transfer.

d)When one sector (or block) of data is available for transfer to the host, the device sets DRQ bit and clears BSY bit. The drive then asserts INTRQ signal.

e)After detecting the INTRQ signal assertion, the host reads the Status register. The host reads one sector of data via the Data register. In response to the Status register being read, the device negates the INTRQ signal.

f)The drive clears DRQ bit to 0. If transfer of another sector is requested, the device sets the BSY bit and steps d) and after are repeated.

Even if an error is encountered, the device prepares for data transfer by setting the DRQ bit. Whether or not to transfer the data is determined for each host. In other words, the host should receive the relevant sector of data (512 bytes of uninsured dummy data) or release the DRQ status by resetting.

Figure 5.2 shows an example of READ SECTOR(S) command protocol, and Figure 5.3 shows an example protocol for command abort.

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Fujitsu MPE3XXXAT manual ∙ Execute Device Diagnostic ∙ Initialize Device Parameters
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MPE3XXXAT specifications

The Fujitsu MPE3XXXAT series is a robust line of hard disk drives (HDDs) known for their reliability, performance, and advanced technology. Designed primarily for enterprise storage solutions, these drives cater to high-demand environments such as data centers, servers, and workstations. With capacities ranging from hundreds of gigabytes to several terabytes, the MPE3XXXAT series offers scalable storage options to accommodate a variety of applications.

One of the standout features of the MPE3XXXAT series is its high rotational speed. With most models operating at 7200 RPM, these drives ensure faster data access and improved read/write performance. This speed makes them ideal for applications requiring quick data retrieval, such as database management and data-intensive workloads. Furthermore, the series utilizes a Serial ATA (SATA) interface, which facilitates seamless connectivity and compatibility with a wide range of systems.

The Fujitsu MPE3XXXAT series is built with advanced technologies that enhance durability and longevity. Notably, the drives incorporate advanced error correction algorithms and vibration resistance features, which are crucial for maintaining data integrity over time. This is particularly important in multi-drive environments where vibrations from one drive can affect the performance of others. The drives are also designed with low power consumption in mind, contributing to energy savings without compromising performance.

In terms of data security, the MPE3XXXAT series supports various security features that protect against unauthorized access. These include ATA security features that enable password protection and robust encryption to safeguard sensitive information from potential breaches. This aspect is particularly significant for enterprises that handle confidential data and require stringent security measures.

The operational temperature range of the MPE3XXXAT drives is optimized for demanding environments, allowing them to function effectively in a variety of conditions. Their reliability is backed by an impressive Mean Time Between Failures (MTBF), which signifies their resilience and the manufacturer's commitment to quality.

Overall, the Fujitsu MPE3XXXAT series stands out as a reliable choice for enterprise storage needs. With its blend of high speed, capacity, durability, and security features, it addresses the challenges faced by modern data centers and businesses that require efficient data management solutions. Whether for backup, archival, or active data storage, the MPE3XXXAT series is designed to deliver consistent performance and peace of mind for users.
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