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Integrated circuits are manufactured on a silicon wafer.

The wafer is cut to produce individual chips. They are then

placed inside a special type of chip package.



A sample of the International Technology R oadmap for Semiconductors.

Moore¶s law: Doubling the number of transistors that could be

placed on a chip every 1.5 to 2 years

Designer may be faced with designing logic circuits that can be

implemented on a single chips OR designing circuits that involve a

number of chips placed on a printed circuit board (PCB).



Different types of Integrated Circuit Chips:

Large variety of chips that implement various functions that areuseful in the design of digital hardware

The chips range from very simple ones with low functionality to

extremely complex chips

Eg. A digital hardware product may require a QP to perform

some arithmetic operations, memory chips to provide storage

capability, and interface chips that allow easy connection to input

and output devices

Three main types of chips:

Standard chips

Programmable logic devices

Custom chips



Standard Chips:

It is popular in the early 1980sThey usually conform to an agreed-upon standard in terms of

functionality and physical configuration

Each SC contains a small amount of circuitry (fewer than 100 T)

Designer chooses the chips that perform needed functions and

defines how these chips should be interconnected to realize a larger

logic circuit

Today, it became inefficient to use valuable space on PCBs for

chips with low functionalityAnother drawback of standard chips is the functionality of each

chip is fixed



A field-programmable gate array (FPGA) chip

Memory block Group of 8 logic cells

Interconnection

wires

Programmable Logic Devices

- General structure- Include collection of

programmable switches

- Design specific applications

by the configured switches

-A bility of programming

multiple times allows making

corrections, prototypes

- Widely used today



Custom-Designed Chips:

PLDs drawback: Consume valuable chip area and limit theoperation speed

Sometimes, it does not meet the designed performance and/or

cost objectives

Solution: the logic circuitry that must be included on the chip is

designed first, then an appropriate technology is chosen to

implement the chip. Finally the chip is manufactured by a company

that has fabrication facilities

It is named as custom design to produce custom chips

Main advantage: design can be optimized for specific task whichusually leads to better performance

A single chip can be used instead of multiple chips to achieve the

same goal, then a smaller area is needed on a PCB.

The cost in producing such chip is high but will be costly

effective if manufacturing in large quantities.



The development process.

Be difficult to automate,

require design experiences

CAD tools used to simulate product behaviors, to

determine if the obtained design meets required specs.



Design concept

Successful design

Initial design

Simulation

Design correct?

Redesign

No

Yes

The basic design loop of digital hardware



A digital hardware system .



A printed circuit board.



Design flow for logic circuits.

Done by the basic design flow

Even functional behavior is

correct, the realized circuit maynot operate properly. Thus need to

implement functional simulation

& timing simulation separately



Completion of PCB

development.

Implementation

Finished PCB

Build prototype

Testing

Correct?

Modify prototype

No

Yes

Minor errors?

Yes

Go to A, B, C, or D in Figure 1.7

No



Logic Circuit Designs:

Mainly use: CPLDs and FPGAs To gain deeper understanding of logic circuits, one should

implement examples using CAD tools

Tools: Altera, Cadence, Mentor Graphics, Synopsys, Synplicity,

Xilinx

In this course:Altera¶s Quartus II CAD system

Date post:	10-Apr-2018
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