2. Agenda
Introduction
Logic Devices
Programmable Logic Devices
PLA
PAL
Field Programmable Gate Array(FPGA)
Architecture
SRAM-based/Flash-based FPGA
Advantages and Limitations of FPGA
Application of FPGA
Current Market Scenarios
3. INTRODUCTION
In the world of digital electronic systems, mostly there are three
basic kinds of devices:
• Memory
• Microprocessor
• Logic Devices
4. LOGIC DEVICES
A logic device is one which can perform any logic function
Logic devices are broadly classified into two Categories:
Fixed
Circuits in a fixed Logic Device are permanent.
Perform one function or set of functions.
The functionality cannot be changed after manufacturing.
Programmable
Standard devices offer a wide range of logic features
The functionality can be changed anytime to perform various logic function
5. PROGRAMMABLE LOGIC DEVICES
ICs with internal logic gates and interconnects
The term Programmable means changing hardware configuration of an internal logic
and interconnects.
These devices allow the end user to specify the logical operation of the device
through a process called “programming”.
6. Types of PLDs
Among the several types of commercial PLDs available, there are two important types:
PLA (Programmable logic array)
Introduced in the year 1970 by Texas Instruments.
Electronic component used to build reconfigurable circuits.
PAL (Programmable array logic)
Introduced in the year 1978 by MMI (Monolithic Memories Inc) .
7. Programmable Logic Array(PLA)
The PLA was developed in the middle 1970s as the first non memory programmable
logic device.
Programmable AND array as well as programmable OR array
Logic functions can be realized using SOP
8. Advantages and Disadvantages of PLAs
Advantages
The architecture of PLA is more flexible.
Frequently used in state machine design.
Disadvantages
Complexity of Programmable Switches
Speed Performance
9. Programmable Array Logic (PAL)
Introduced in the year 1978 by MMI (Monolithic Memories Inc)
Programmable AND plane, but Fixed OR plane
10. Advantages and Disadvantages of PALs
Advantages
Frequently used in practical applications.
Less expensive and offer better performance than PLA.
Disadvantages
Limited inputs to the OR gates.
11. Field Programmable Logic Devices
To retain the advantages and to overcome the disadvantages of PLAS and PALS the
newly introduced devices are known as FPGAs
What do they do?
These are reprogrammable(re-configurable) logic devices .
Designers use software to develop any digital circuit they like and they configure
the chip to perform the function
They are very fast– much faster than a microcontroller.
12. FPGAs
A field programmable gate array (FPGA) is a Programmable Logic
Device(PLD) with higher densities and capable of implementing different
functions in a short periodof time.
14. Architecture of FPGA
Elements of FPGA
Basic elements of an Field Programmable Gate Array are:
CLB (Configurable Logic Block) includes digital logic, inputs, outputs.
Interconnects provide connection between the logic blocks to implement the user
logic.
PSM (Programmable Switch Matrix) provides switching between interconnects.
I/O Pads used for the outside world to communicate with different applications.
16. Configuring Look-Up Table (LUT)
a
b
c
y
y a b c
a b c y
0 0 0 1
0 0 1 0
0 1 0 1
0 1 1 1
1 0 0 1
1 0 1 0
1 1 0 1
1 1 1 1
Required Function Truth Table Programmed LUT
1
0
1
1
1
0
1
1
MUX y
a,b,c
LUT
The contents of LUT are programmed at power up
17. FPGA Implementation Technologies
FPGA (Field Programmable Gate Array) is an integrated circuit containing gate matrix
which can be programmed by the user “in the field”.
Configuration bitstream can be stored in FPGA using various technologies.
Eg: SRAM based FPGA, Flash based FPGA , Antifuse based FPGA
The majority of FPGAs is based on SRAM (Static RAM).
18. SRAM - FPGA
SRAM-based FPGA stores logic cells configuration data in the static memory.
Since SRAM is volatile and can't keep data without power source, such FPGAs must
be programmed (configured) upon start.
There are two basic modes of programming:
• Master mode – Reads configuration from External source.
• Slave mode – Configured by an External master device.
SRAM-based FPGAs include most chips of Xilinx Virtex and Spartan families
19. Flash based - FPGA
Flash-based FPGA uses flash as a primary resource for configuration storage
This technology has an advantage of being less power consumptive
Flash-based FPGAs are also more tolerant to radiation effects
Flash-based FPGA families such as Igloo and ProASIC3 are manufactured by Actel.
20. Advantages of FPGA
High Gate Density as compared to microcontrollers.
Super Fast as compared to ARM processors
Massively Parallel
High I/O Count as compared to microcontroller.
Field Programmable-Reprogram ability
21. Limitations of FPGA
It is Expensive as compared to ASIC chip.
High Power consumption as compared to Low power processor or
microcontroller.
Volatile in nature.
23. Current Market of FPGA
Expected to be valued at $9.50 billion by 2023 from 5.83 billion in 2017
Telecommunication held the largest size of FPGA market in 2016.
Key players in FPGA market – Xilinx(US) Intel(US) Lattice Semiconductor
(US) United Microelectronics (Taiwan)
However , the inability of FPGA to substitute for ASIC devices is still the major
challenge in the market.
http://www.rnrmarketresearch.com/global-and-chinese-field-programmable-gate-
arrays-fpga-industry-2018-market-research-report-market-report.html
