Intel 8XC251SB, 8XC251SA, 8XC251SP, 8XC251SQ manual Notational Conventions and Terminology, Italics

GUIDE TO THIS MANUAL

Appendix B, “Signal Descriptions” — describes the function(s) of each device pin. Descrip- tions are listed alphabetically by signal name. This appendix also provides a list of the signals grouped by functional category.

Appendix C, “Registers” — accumulates, for convenient reference, copies of the register defi- nition figures that appear throughout the manual.

A glossary has been included for your convenience.

1.2NOTATIONAL CONVENTIONS AND TERMINOLOGY

The following notations and terminology are used in this manual. The Glossary defines other terms with special meanings.

#	The pound symbol (#) has either of two meanings, depending on the
	context. When used with a signal name, the symbol means that the
	signal is active low. When used in an instruction, the symbol prefixes
	an immediate value in immediate addressing mode.
italics	Italics identify variables and introduce new terminology. The context
	in which italics are used distinguishes between the two possible
	meanings.
	Variables in registers and signal names are commonly represented by
	x and y, where x represents the first variable and y represents the
	second variable. For example, in register Px.y, x represents the
	variable [1–4] that identifies the specific port, and y represents the
	register bit variable [7:0]. Variables must be replaced with the correct
	values when configuring or programming registers or identifying
	signals.
XXXX	Uppercase X (no italics) represents an unknown value or a “don’t
	care” state or condition. The value may be either binary or
	hexadecimal, depending on the context. For example, 2XAFH (hex)
	indicates that bits 11:8 are unknown; 10XX in binary context
	indicates that the two LSBs are unknown.
Assert and Deassert	The terms assert and deassert refer to the act of making a signal
	active (enabled) and inactive (disabled), respectively. The active
	polarity (high/low) is defined by the signal name. Active-low signals
	are designated by a pound symbol (#) suffix; active-high signals have
	no suffix. To assert RD# is to drive it low; to assert ALE is to drive it
	high; to deassert RD# is to drive it high; to deassert ALE is to drive it
	low.

1-3