Reading Databook Symbols

Symbol

Definition

0

Logic Low

1

Logic High

HL

High to Low Transition

LH

Low to High Transition

Positive Clock Edge

Negative Clock edge

Tin

Input Transition 30 to70 %

Delay

50 to 50%

Tout

Output Transition 30 to 70%

?

Don’t Care (Combinatorial Cells)

X

Don’t Care (Sequential Cells)

default

No “when” condition for Input

n/a

No Transition