Samsung 3.5" hard disk drives manual Physical Interface, Signal Conventions, Signal Summary

DISK DRIVE OPERATION

CHAPTER 6 AT INTERFACE AND ATA COMMANDS

6.1Introduction

A Samsung disk drive with an Embedded AT Interface fully supports and enhances PC mass storage requirements. The Samsung AT interface conforms to the ATA/ATAPI-6 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.

6.2Physical Interface

6.2.1Signal Conventions

Signal names are shown in all upper case letters. Signals can be asserted (active, true) for 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 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 (/). The asserted low function name is 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 implementer.

6.2.2Signal Summary

The physical interface consists of single-ended TTL compatible receivers and drivers communicating through a 40/80-conductor flat ribbon non-shielded cable using an asynchronous interface protocol. The pin numbers and signal names are shown in Table 6-1.Reserved signals are left unconnected.

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