3.4 Maintenance, Diagnostic Commands

3.4.4 READ BUFFER (3C)

 

Bit

7

6

5

4

 

3

 

2

 

1

0

Byte

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

X‘3C’

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

LUN

 

0

 

 

 

 

Mode

 

 

 

 

 

 

 

 

 

 

 

 

2

 

 

 

X‘00’ (Buffer ID)

 

 

 

 

 

 

 

 

 

 

 

 

 

3

 

 

 

Buffer Offset (MSB)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

 

 

 

Buffer Offset

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5

 

 

 

Buffer Offset

(LSB)

 

 

 

 

 

 

 

 

 

 

 

 

 

6

 

 

 

Transfer Byte Length (MSB)

 

 

 

 

 

 

 

 

 

 

 

 

 

7

 

 

 

Transfer Byte Length

 

 

 

 

 

 

 

 

 

 

 

 

 

8

 

 

 

Transfer Byte Length (LSB)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9

 

0

0

0

0

0

 

0

 

0

Link

 

 

 

 

 

 

 

 

 

 

 

 

 

This command is used in combination with the WRITE BUFFER command to diagnose the normalcy of the IDD’s data buffer memory and the SCSI bus.

The IDD have a 7680 K byte size data buffer.. In this command, each data byte position in the data buffer must be specified in 4-byte units using buffer addresses within the range X'000000' to X'77FFFF'.

The functions of this command and the contents of the data transferred to the INIT are specified by the “Mode” field in the CDB and one of the transfer modes shown below can be selected.

“Mode” Bit

3

2

1

0

Transfer Mode

 

 

 

 

 

 

 

0

0

0

0

Header + Data, without Address Specification

 

0

0

0

1

Header + Data, with Address Specification

 

0

0

1

0

Data Only, with Address Specification

 

0

0

1

1

Buffer Descriptor

 

1

0

1

0

Echo buffer

 

1

0

1

1

Echo buffer descriptor

 

 

 

 

 

 

(1)Mode = 0, 0, 0, 0: Header + data, without address specification

When this mode is specified, the data stored in the IDD’s data buffer are transferred to the INIT after the 4-byte header. Zero must be specified in the “Buffer offset” field in the CDB.

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Page 169
Image 169
Fujitsu MAS3367, MAP3367, MAP3147, MAS3735, MAP3735 specifications Read Buffer 3C, Lun
Page 168 Page 170

MAP3735, MAP3147, MAS3367, MAP3367, MAS3735 specifications

Fujitsu, a renowned leader in technology and innovation, has developed a variety of reliable hard disk drives (HDDs) that cater to a wide range of data storage needs. Among these, the MAS3735, MAP3367, MAS3367, MAP3147, and MAP3735 series stand out for their advanced features and exceptional performance.

The MAS3735 is a high-capacity enterprise-class drive that boasts a storage capacity of up to 300 GB. Its 10,000 RPM spindle speed ensures rapid data retrieval and efficient performance, making it ideal for data-intensive applications. It utilizes a Serial Attach SCSI (SAS) interface, which allows for improved data transfer rates and increased reliability compared to traditional SATA drives. The drive is designed with advanced technologies such as error recovery and data integrity features, ensuring the safety and security of critical data.

Similarly, the MAP3367 and MAS3367 models are geared towards both enterprise and mid-range server environments, providing a storage capacity of up to 300 GB as well. These drives also operate at a spindle speed of 15,000 RPM, offering swift access times that enhance overall system performance. The MAP3367 employs the Ultra 320 SCSI interface, allowing for significant bandwidth and ensuring data is transmitted efficiently.

On the other hand, both MAP3147 and MAP3735 models provide versatile solutions for various applications, supporting capacities from 36 GB to 147 GB. The MAP3147, with its 10,000 RPM speed, is optimized for workloads requiring quick access and high throughput, making it suitable for transactional systems and enterprise applications. The MAP3735, while offering comparable capacity, emphasizes exceptional reliability and durability, which is crucial for environments that involve heavy data loads.

All these Fujitsu HDDs are characterized by their robust construction, reliability, and efficiency. They are built to withstand heavy workloads and are equipped with features like advanced thermal management and acoustic noise reduction, ensuring they operate effectively in data center environments.

In conclusion, Fujitsu's MAS3735, MAP3367, MAS3367, MAP3147, and MAP3735 series HDDs are designed for high performance and reliability, catering to both enterprise and mid-range environments. Their advanced features make them a strong choice for businesses looking to enhance their storage solutions while maintaining data integrity and system performance.
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