ATA (SATA), an evolutionary high-performance
interface for storage devices to replace the Parallel ATA, is
used to connect ATA and ATAPI devices, including CDs, DVDs, tapes
devices, high capacity removeable devices, zip drives, and CD-RWs.
with parallel ATA interface, Serial ATA addresses some shortcomings and
provides a scalable platform to support several generations of future
ATA is a drop-in solution that is compatible with today's software,
which runs on the new architecture without modification. It provides for
systems which are easier to design, with cables that are simple to route
and install, smaller cable connectors, improve silicon design, and lower
voltages which alleviate current design requirements in Parallel ATA.
ATA requires integrated circuits to tolerate input signals as high as 5
volts. Serial ATA reduces the signaling voltages to approximately 250
millivolts (¼ volt).
Efficiency. The parallel ATA
interface has 26 signal pins going into the interface chip. Serial ATA
uses only 4 signal pins, improving the pin efficiency and accommodating
a highly integrated chip implementation.
Cable and Connector Plant. The
parallel ATA cable and connector plant is a bulky cable made up of
unwieldy 80 conductor ribbon cables and 40 pin header connectors. Serial
ATA uses a much smaller serial cable similar in appearance to modern
telephone cables. Eliminating the cable nest improves the systemˇ¦s
airflow and cooling, and offers greater freedom in chassis design.
Interaction. With todayˇ¦s
parallel ATA implementation, pairs of devices share a common cable in a
master-slave relationship. This interaction between devices results in
the available bandwidth being shared between the devices. Additionally,
since the devices on the cable interact, they must be jointly qualified,
resulting in the substantial expansion of the system integratorsˇ¦
qualification matrix in order to comprehend all possible combinations of
ATA is a point-to-point interface where each device is directly
connected to the host via a dedicated link. Each device, therefore, has
the entire interface bandwidth dedicated to it, and there is no
interaction between devices. This means software can be streamlined,
eliminating the overhead associated with coordinating accesses between
the master and slave device sharing the same cable.
ATA is compatible at the register level with parallel ATA. This means
Serial ATA requires no changes to existing software and operating
systems in order to function, and it provides backward compatibility
with existing operating environments. It has already been demonstrated
to run with Microsoft Windows* 98, Microsoft Windows 2000, and Linux
operating systems without the need for any special software drivers.