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