Samsung M8 manual Physical Interface Signal Summary, Signal Descriptions

PRIMITIVE-A primitive is a single Dword of information that consists of a control character in byte 0 followed by three additional data characters in bytes 1-3.

SHADOW REGISTER BLOCK REGISTERS-Shadow Register Block registers are interface registers used for delivering commands to the device or posting status from the device.

SQUELCH-This block establishes a limit so that detection of a common mode signal can be properly accomplished.

WORD-A word is sixteen (16) bits of data. A word may be represented as 16 bits or as two adjacent bytes. When shown as bits the least significant bit is bit 0 and most significant bit is bit 15. The most significant bit is shown on the left. When shown as bytes the least significant byte (lower) byte is byte 0 and the most significant byte (upper) byte is byte 1.

6.2Physical Interface

For information please consult the document entitled “Serial ATA: High Speed Serialized AT Attachment Revision 1.0a” released on February 4, 2003 available from the Internet http://www.serialata.org/ still retrievable on May 29, 2003. Section 6 of the document contains physical layer specifications related topics.

6.3Signal Summary

For details, please consult the document entitled “Serial ATA: High Speed Serialized AT Attachment

Revision 1.0a” released on February 4, 2003 and “Serial ATA II: Extensions to Serial ATA 1.0a Revision 1.2” released on September 30, 2004 available from http://www.serialata.org/ retrieved and available on Jan 6, 2005.

6.3.1Signal Descriptions

For data packets and additional information please consult the document entitled “Serial ATA: High Speed

Serialized AT Attachment Revision 1.0a” released on February 4, 2003 and “Serial ATA II: Extensions to Serial ATA 1.0a Revision 1.2” released on September 30, 2004 available from http://www.serialata.org/ retrieved and available on Jan 6, 2005.

A device can operate in either of two addressing modes, CHS or LBA, on a command-by-command basis. The CHS mode is supported for legacy command access only. The task file registers contains the Cylinder, Head, and Sector information of a requested location. Because the disk drive has its own mapping, the CHS mode is translated into disk drive physical address by the HDD firmware. There is no direct relationship of the CHS that can be accessed from the host.

This CHS term defines the addressing mode of the device as being by physical sector address. The physical sector address is made up of three fields: the sector number, the head number and the cylinder number. Sectors are numbered from 1 to a device specific maximum value, which cannot exceed 255. Heads are numbered from 0 to a device specific maximum value, which cannot exceed 15. Cylinders are numbered from 0 to a device specific maximum value, which cannot exceed 65,535. Typically, sequential access to the media is accomplished by treating the sector number as the least significant portion, the head number as the mid portion, and the cylinder number as the most significant portion of the CHS address.

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