• What is FPGA?

• History of FPGA

• ASICs and ASSPs Vs. FPGA.

• FPGA Application.

• List and comparison of FPGA companies

• FPGA Architecture.

• Altera FPGA Series

FPGA

Field-programmable gate array

Prepared By-

Mohammed Abdul Kader

Lecturer, EEE, IIUC

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 2

What is an FPGA?

The field-programmable gate array (FPGA) is a semiconductor device that can be programmed

after manufacturing. Instead of being restricted to any predetermined hardware function, an FPGA

allows you to program product features and functions, adapt to new standards, and reconfigure

hardware for specific applications even after the product has been installed in the field—hence the

name "field-programmable". You can use an FPGA to implement any logical function that an

application-specific integrated circuit (ASIC) could perform, but the ability to update the

functionality after shipping offers advantages for many applications.

An FPGA contains programmable logic components called logic elements (LEs) and a hierarchy of

reconfigurable interconnects that allow the LEs to be physically connected. You can configure LEs to

perform complex combinational functions, or merely simple logic gates like AND and XOR. In

most FPGAs, the logic blocks also include memory elements, which may be simple flipflops or

more complete blocks of memory.

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 3

• Field Programmable Gate Arrays popularly known as FPGAs is an alternative for implementation of

digital logic in systems. They are prefabricated silicon chips that can be programmed electrically to

implement any digital design.

• The first static memory-based FPGA (commonly called as SRAM based FPGA) was proposed by

Wahlstrom in 1967. This architecture allowed for both logic and interconnection configuration using

a stream of configuration bits.

• Later on the first commercial modern-era FPGA was introduced by Xilinx in 1984. It contained the

low classic array of Configurable Logic Blocks (CLBs) and inputs/outputs.

• From that of first FPGA which contain 64 CLBs and 58 inputs and outputs , FPGAs have grown

enormously in complexity. Today’s modern FPGA now can contain approximately 330,000 logic

blocks and around 1100 inputs and outputs.

• The basic architecture of FPGA consists of three major components: programmable logic blocks

which implements the logic functions, programmable routing (interconnects) to implement these

functions and I/O blocks to make off-chip connections.

History of FPGA

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 4

ASICs and ASSPs

An application-specific integrated circuit (ASIC) is an integrated circuit composed of electrical

components, such as transistors, capacitors, and resistors, usually fabricated on a wafer composed of

silicon or other semiconductor material that is customized for a particular use. Two examples of ASICs

are a voice recorder or a high-efficiency Bitcoin miner.

Application-specific standard products (ASSPs), on the other hand, are ICs that are dedicated to

a specific application market and sold to more than one user (and hence, standard) in contrast to ASICs,

which are designed and sold to a single customer. Some examples of ASSPs are microcontrollers and the

system chips at the hearts of many smartphones and tablets.

ASICs and ASSPs are specifically designed for dedicated functionality. Because of the tight control of

their configuration, ASICs and ASSPs are very compact, inexpensive, fast, and low-power, which are all

highly desirable traits in electronics design. Because their function is hard-wired at the time of

manufacture, it isn’t easy to change the functionality of a small part of the circuit. In fact, because these

circuits are permanently fabricated on silicon wafers, you simply can’t take apart the circuitry and

replace it with something else. If you need to change something in the design, you have to scrap the

whole chip and start from scratch.

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 5

Compared to ASICs or ASSPs, FPGAs offer many design advantages, including:

• Rapid prototyping

• Shorter time to market

• The ability to re-program in the field for debugging

• Lower NRE costs

• Long product life cycle to mitigate obsolescence risk

Advantages of FPGA over ASICs and ASSPs

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 6

FPGA Applications

Due to their programmable nature, FPGAs are an ideal fit for many different

markets such as:

•Aerospace & Defense - Radiation-tolerant FPGAs along with intellectual property

for image processing, waveform generation, and partial reconfiguration for SDRs.

•ASIC Prototyping - ASIC prototyping with FPGAs enables fast and accurate SoC

system modeling and verification of embedded software

•Audio - FPGAs and targeted design platforms enable higher degrees of flexibility,

faster time-to-market, and lower overall non-recurring engineering costs (NRE) for a

wide range of audio, communications, and multimedia applications.

•Automotive - Automotive silicon and IP solutions for gateway and driver assistance

systems, comfort, convenience, and in-vehicle infotainment.

•Broadcast - Adapt to changing requirements faster and lengthen product life cycles

with Broadcast Targeted Design Platforms and solutions for high-end professional

broadcast systems.

•Consumer Electronics - Cost-effective solutions enabling next generation, full-

featured consumer applications, such as converged handsets, digital flat panel

displays, information appliances, home networking, and residential set top boxes.

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 7

•Data Center - Designed for high-bandwidth, low-latency servers, networking, and

storage applications to bring higher value into cloud deployments.

•High Performance Computing and Data Storage - Solutions for Network Attached

Storage (NAS), Storage Area Network (SAN), servers, and storage appliances.

•Industrial - FPGAs and targeted design platforms for Industrial, Scientific and

Medical (ISM) enable higher degrees of flexibility, faster time-to-market, and lower

overall non-recurring engineering costs (NRE) for a wide range of applications such

as industrial imaging and surveillance, industrial automation, and medical imaging

equipment.

•Medical - For diagnostic, monitoring, and therapy applications, FPGA families can

be used to meet a range of processing, display, and I/O interface requirements.

•Security - FPGA offers solutions that meet the evolving needs of security

applications, from access control to surveillance and safety systems.

•Video & Image Processing - FPGAs and targeted design platforms enable higher

degrees of flexibility, faster time-to-market, and lower overall non-recurring

engineering costs (NRE) for a wide range of video and imaging applications.

•Wired Communications - End-to-end solutions for the Reprogrammable Networking

Linecard Packet Processing, Framer/MAC, serial backplanes, and more

•Wireless Communications - RF, base band, connectivity, transport and networking

solutions for wireless equipment, addressing standards such as WCDMA, HSDPA,

WiMAX and others.

FPGA Applications (Cont.)

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 8

List and comparison of FPGA companies /manufacturers

• Xilinx

• Altera

• Lattice Semiconductor

• Microsemi (was Actel)

• QuickLogic

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 9

Each FPGA vendor has its own FPGA architecture, but in general terms they are all a variation of that

shown in Fig . The architecture consists of –

• Configurable logic blocks,

• Configurable I/O blocks, and

• Programmable interconnect.

FPGA Architecture

Also, there will be clock circuitry for

driving the clock signals to each logic

block. Additional logic resources such as

ALUs, memory, and decoders may also

be available.

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 10

Configurable Logic Blocks (CLBs): These blocks contain the logic for the FPGA. In the large-grain

architecture used by all FPGA vendors today, these CLBs contain enough logic to create a small state

machine as illustrated in Fig . The block contains RAM for creating arbitrary combinatorial logic

functions, also known as lookup tables (LUTs). It also contains flip-flops for clocked storage elements,

along with multiplexers in order to route the logic within the block and to and from external resources.

The multiplexers also allow polarity selection and reset and clear input selection.

FPGA Architecture (Cont.)

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 11

Configurable I/O Blocks: A Configurable input/output (I/O) Block, as shown in Fig, is used to

bring signals onto the chip and send them back off again. It consists of an input buffer and an output

buffer with three-state and open collector output controls. Typically there are pull up resistors on the

outputs and sometimes pull down resistors that can be used to terminate signals and buses without

requiring discrete resistors external to the chip. The polarity of the output can usually be programmed

for active high or active low output, and often the slew rate of the output can be programmed for fast or

slow rise and fall times.

There are typically flip-flops on outputs

so that clocked signals can be output

directly to the pins without encountering

significant delay, more easily meeting the

setup time requirement for external

devices. Similarly, flip-flops on the inputs

reduce delay on a signal before reaching

a flip-flop, thus reducing the hold time

requirement of the FPGA.

FPGA Architecture (Cont.)

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 12

Programmable Interconnect: In Fig , a hierarchy of interconnect resources can be seen. There are

long lines that can be used to connect critical CLBs that are physically far from each other on the chip

without inducing much delay. Theses long lines can also be used as buses within the chip. There are also

short lines that are used to connect individual CLBs that are located physically close to each other.

Transistors are used to turn on or off connections between different lines. There are also several

programmable switch matrices in the FPGA to connect these long and short lines together in specific,

flexible combinations.

Three-state buffers are used to connect many

CLBs to a long line, creating a bus. Special long

lines, called global clock lines, are specially

designed for low impedance and thus fast

propagation times. These are connected to the

clock buffers and to each clocked element in

each CLB. This is how the clocks are distributed

throughout the FPGA, ensuring minimal skew

between clock signals arriving at different flip-

flops within the chip.

FPGA Architecture (Cont.)

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 13

Clock Circuitry: Special I/O blocks with special high drive clock buffers, known as clock drivers, are

distributed around the chip. These buffers connect to clock input pads and drive the clock signals onto the

global clock lines. These clock lines are designed for low skew times and fast propagation times.

FPGA Architecture (Cont.)

FPGA Architecture

Its easy to see that FPGAs can be summed up as islands of configurable "Logic Blocks" in a sea of

programmable interconnect. The beauty of FPGAs is that both the Logic Blocks & the Interconnect are

programmable.

Lecture Materials on "FPGA", By- Mohammed Abdul Kader, Lecturer, EEE, IIUC 14

Altera FPGA Series

Altera offers customers a broad spectrum of FPGAs geared towards diverse markets and applications.

Cyclone FPGAs

Cyclone® series FPGAs are the industry's lowest cost, lowest power FPGAs, ideal for high-volume,

cost-sensitive applications.

Use a Cyclone series FPGA alone, as a digital signal processor, or as a cost-effective embedded

processing solution. Cyclone series FPGAs offer a wide range of density, memory, embedded

multiplier, and packaging options. Newer families include integrated transceiver options (at data rates

up to 5G).

Arria FPGAs

Arria® series FPGA provide an optimal balance of performance, power, and price for mid-range

transceiver-based applications. You'll find a rich feature set of functions (memory, logic, and DSP)

combined with superior signal integrity in the devices.

Arria series FPGAs feature on-chip transceivers that allow you to integrate more functions and maximize

system bandwidth (at data rates up to 10G).

Stratix® series FPGAs are the industry's highest bandwidth, highest density FPGAs, ideal for high-end

applications. Newer families come with integrated transceiver options (at data rates up to 28G).

Stratix series FPGAs simplify the challenges of signal integrity by providing transceivers with best-in-

class jitter characteristics. Features such as Programmable Power Technology keep total power in check.

Stratix FPGAs