In order to understand SATA, you must first understand ATA. This includes understanding the ATA Architecture, the Protocol, the Task Register Interface, and the Command Sets used to store and retrieve information. This chapter provides an introduction to Serial ATA technology. You will learn about the following topics:

1. What ATA is and how it impacts SATA 2. SATA Standards and Specifications

a. Standards work done by INCITS T-13 Working Group i. ATA/ATAPI 1-6 for parallel ATA ii. ATA/ATAPI 7 for Serial ATA iii. ATA-8 for SCSI, such as protocol layer segmentation (e.g., Command, Transport,

and Physical layer Standards) iv. Approved ANSI references for all ATA-related Standards

b. Specification work done by the SATA International Organization (SATA-IO) i. Chronological list of Specifications ii. Key technology entry points (e.g., port selectors, port multipliers, etc.) 3. SATA protocol layers

a. Application b. Transport c. Link d. Physical

4. I/O register model and how it relates to SATA 5. Important registers, including COMMAND, STATUS, ERROR, and DEVICE 6. CHS LBA addressing, translation, and 48-bit addressing 7. ATA protocols, including PIO, DMA, and PACKET 8. Serial link characteristics, including differential signaling, encoding, and primitives 9. Idle links 10. Frame transmission 11. Link layer protocol

12. Transport layer protocol, including basic Frame Information Structures (FIS) and numerous frame payloads

13. Application layer basics, including register input and outputs

The acronym “ATA” stands for “AT Attachment.” The “AT” stands for “Advanced Technology,” its usage derived from the IBM PC/AT personal computer that was produced in the 1980s. ATA referred to the technology that was used to connect both floppy and hard disk drives in those early PC systems. Bear in mind that a 40-MB capacity 5.25” hard drive was considered leading edge technology at this time and that CD-ROMs had yet to make an appearance. For over two decades, ATA has become a ubiquitous technology in the PC market place, and the ATA legacy command set may survive for the next ten years. Around 2002, the parallel ATA interface achieved obsolescence and was replaced with SATA in all client systems.