| Hard
Macro (Macro Cell) |
A logic function defined by the manufacturer of an
application-specific integrated circuit. The function is described in terms of the simple
functions provided in the cell library and the connections between them. The manufacturer
also defines how the cells forming the macro will be assigned to basic cells and the
routing of tracks between the basic cells.
|
| a |
| Hardware |
Generally understood to refer to any of the
physical portions constituting an electronic system, including components, circuit boards,
power supplies, cabinets, and monitors.
|
| a |
| Hertz |
Unit of frequency. One Hertz equals one cycle,
or one oscillation, per second.
|
| a |
| Hetrojunction |
The interface between two regions of
dissimilar semiconductor materials. The interface of a hetrojunction has naturally
occurring electric fields which can be used to accelerate electrons, and transistors
created using hetrojunctions can switch much faster than their counterparts of the same
size.
|
| a |
| Hexadecimal |
Base-16 numbering system. Each hexadecimal
digit can be directly mapped onto four binary digits, or bits.
|
| a |
| High Impedance State |
The state on a signal that is not being driven
by any value. A high-impedance state is indicated by the character Z.
|
| a |
| Hologram |
A three-dimensional image (from the Greek:
holos meaning "whole" and gram meaning "message").
|
| a |
| Holographic Interconnect |
A form of optical interconnect based on a thin
slice of quartz, into which three-dimensional images are cut using a laser beam. Thus, the
quartz is referred to as a computer-generated hologram, and this interconnection strategy
is referred to as holographic.
|
| a |
| Holography |
The art of obtaining three-dimensional images
known as holograms.
|
| a |
| Homojunction |
An interface between two regions of
semiconductor having the same basic composition but opposing types of doping.
Homojunctions dominate current processes because they are easier to fabricate than
hetrojunctions.
|
| a |
| Hybrid |
An electronic sub-system in which a number of
integrated circuits (packaged and/or unpackaged) and discrete components are attached
directly to a common substrate. Connections between the components are formed on the
surface of the substrate, and some components such as resistors and inductors may be
fabricated directly onto the substrate.
|
| a |
| Hydrogen Bond |
The electrons in a water molecule are not
distributed equally, because the oxygen atom is a bigger, more robust fellow which grabs
more than its fair share. The end result is that the oxygen atom has an overall negative
charge, while the two hydrogen atoms are left feeling somewhat on the positive side. This
unequal distribution of charge means that the hydrogen atoms are attracted to anything
with a negative bias; for example, the oxygen atom of another water molecule. The
resulting bond is known as a hydrogen bond.
|
| a |
| Hz (Hertz) |
Unit of frequency. One Hertz equals one cycle, or one oscillation, per
second.
|