WA31273A / WA32543A / WA33203A / WA32163A / WA31083A / WA32162A 6-1
Chapter 6
AT INTERFACE and ATA COMMANDS
6-1
Introduction
A SAMSUNG Disk Drive with an Embedded AT Interface fully supports and enhances
the PC mass storage requirements. The SAMSUNG AT interface conforms to the ANSI
CAM (X3T9.2) standards in Cabling, in Physical Signals, and in Logical Programming
schemes. The SAMSUNG Embedded AT controller joins the industry premiere VLSI
circuitry with ingenious programming skill that does not compromise performance or
reliability. SAMSUNG integrates and delivers the cutting edge in technology.
SAMSUNG AT class disk drives are designed to relieve and to enhance the I/O request
processing function of system drivers.
6-2
Physical Interface
6-2-1 Signal Conventions
Signal names are shown in all upper case letters. Signals can be asserted (active, true)
either a high (more positive voltage) or low (less positive voltage) state. A dash
character (-) at the beginning or end of a signal name indicates that it is asserted at the
low level (active low). No dash or a plus character (+) at the beginning or end of a signal
name indicates it is asserted high (active high). An asserted signal may be driven high or
low by an active circuit, or it may be allowed to be pulled to the correct state by the bias
circuitry.
Control signals that are asserted for one function when high and asserted for another
function when low are named with the asserted high function name followed by a slash
character (/), and the asserted low function name followed with a dash (-), e.g.
BITENA/BITCLR- enables a bit when high and clears a bit when low. All signals are
TTL compatible unless otherwise noted. Negated means that the signal is driven by an
active circuit to the state opposite to the asserted state (inactive, or false) or may be
simply released (in which case the bias circuitry pulls it inactive, or false), at the option
of the implementor.
