Definitions and Timing Conventions

DEFINITIONS

an input level is guaranteed to appear

as a logical one This parameter is to

be measured by performing a function-

al test at reduced clock speeds and

nominal timing (ie not minimum setup

and hold times or output strobes) with

the high level of all driving signals set

applied to the device

an input level is guaranteed to appear

as a logical zero to the device This pa-

rameter is measured in the same man-

voltages applied to the device

which an output placed in a logical one

state will converge when loaded at the

maximum specified load current

which an output placed in a logical zero

state will converge when loaded at the

maximum specified load current

Threshold Region

The threshold region is the range of in-

Valid Signal

A signal is Valid if it is in one of the valid

deemed valid at the instant it enters a

valid state

Invalid Signal

A signal is Invalid if it is not in a valid

logic state ie when it is in the thresh-

ing specifications a signal is deemed

Invalid at the instant it enters the

threshold region

TIMING CONVENTIONS

For the purposes of this timing specification the following

conventions apply

Input Signals

All input signals may be characterized

Period

The period of clock signal is designated

monic of the clock signal being speci-

fied

Rise Time

where yy represents a mnemonic of the

signal whose rise time is being speci-

Fall Time

where yy represents a mnemonic of the

signal whose fall time is being speci-

Pulse Width High

The high pulse width is designated as

monic of the input or output signal

whose pulse width is being specified

High pulse widths are measured from

Pulse Width Low

The low pulse width is designated as

monic of the input or output signal

whose pulse width is being specified

Low pulse widths are measured from

Setup Time

where ww represents the mnemonic of

the input signal whose setup time is be-

ing specified relative to a clock or

strobe input represented by mnemonic

xx Setup times are measured from the

ww Valid to xx Invalid

Hold Time

where ww represents the mnemonic of

the input signal whose hold time is be-

ing specified relative to a clock or

strobe input represented by mnemonic

xx Hold times are measured from xx

Valid to ww Invalid

Delay Time

Delay

times

are

designated

as

mnemonic of the input reference signal

and yy represents the mnemonic of the

output signal whose timing is being

specified relative to xx The mnemonic

may optionally be terminated by an H

or L to specify the high going or low

going transition of the output signal

Maximum delay times are measured

from xx Valid to yy Valid Minimum de-

lay times are measured from xx Valid to

yy Invalid This parameter is tested un-

der the load conditions specified in the

Conditions column of the Timing Speci-

fications section of this data sheet

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