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FPGA's are programmable devices that can be programmed to do almost any type of hardware function available. You can have it function as a processor one time or if you want to reprogram it you can make it into a uart or other types of hardware functions. The only catch is normally FPGA's can only run so fast, I beleive currently you can get FPGA's that run up to like 100Mhz or so.
FPGA stands for Fileld programmable gate array. The importance of this the chip can be programmed on the field that is after the system has been taken u can programme it depending on u'r requirment.
Basically FPGA consist of logic blocks, i/o blocks, interconnect matrix also some ram blocks. The three major types of fpga's are:
1. single function
2. multiple function
3. Application specific
If you search the www.Xillix.com or www.Altera.com websites, you can get some information. To understand the internal structure, you need some knowledge of digital circuit. To be able to use FPGA, you need to learn VHDL or verilog hardware programming languages.
FPGA is close related to CPLD (Complex Programmable Logic Device), but there are some differencies in the technologies.
Search EDAboard and Google to find out about the main differencies.
Xilinx and Altera is the two biggests vendors of FPGA and CPLD.
There are different languages used to program Programmable devices, just like there is different languages to program microcontrollers like C, C++ and Pascal.
The two biggest languages used to program FPGA is VHDL and Verilog.
VHDL is most common used in Europe, while Verilog is more common in America, but both Programmable Logic languages are used all over the world. Both CPLDs and FPGAs are programmed from the same programs.
You can search EDAboard for Verilog or VHDL eBooks to learn about the languages and how to use FPGAs and CPLDs.
There are some new Programming languages introduced at the moment, but I think you should start with learning either VHDL or Verilog.
They say that Verilog is easiest to learn if you come from a software background, while VHDL is easier to learn if you come from a Hardware background. Some engineering colleges teaches in VHDL while others teaches in Verilog, I guess you can learn both languges at some colleges. But start by choosing one of them to learn.
If you search EDAboard og Google for CPLD, FPGA, VHDL or Verilog you will find a lot of info about the subject.
You should also check out www.altera.com and www.xilinx.com
What are FPGAs?
FPGAs are programmable digital logic chips. What that means is that you can program them to do almost any digital function.
Here's the general workflow when working with FPGAs:
You use a computer to describe the "logic function" that you want. You might draw a schematic, or create a text file describing the function, doesn't matter.
You compile the "logic function" on your computer, using a software provided by the FPGA vendor. That creates a binary file that can be downloaded into the FPGA.
You connect a cable from your computer to the FPGA, and download the binary file to the FPGA.
That's it! Your FPGA behaves according to your "logic function".
Keep in mind that
You can download FPGAs as many time as you want - no limit - with different functionalities every time if you want. If you make a mistake in your design, just fix your "logic function", re-compile and re-download it. No PCB, solder or component to change.
The designs can run much faster than if you were to design a board with discrete components, since everything runs within the FPGA, on its silicon die.
FPGAs loose their functionality when the power goes away (like RAM in a computer that looses its content). You have to re-download them when power goes back up to restore the functionality.
Who makes FPGAs?
There are (at least) 5 companies making FPGAs in the world. The first two (Xilinx and Altera) hold the bulk of the market.
Xilinx is the biggest name in the FPGA world. It tends to be the density and technology leader.
Altera is the second FPGA heavyweight, also a well-known name.
Lattice, Actel, Quicklogic are much smaller and are the "specialty shops".
Xilinx
Xilinx has traditionally been the silicon technology leader.
Biggest and most flexible (feature-full) devices.
Complex architecture.
Xilinx general philosophy is to provide all the features possible, at the cost of extra complexity. Altera philosophy is different.
Altera
Lean and efficient device architectures.
Easy to use devices, less features.
Lattice, Actel and Quicklogic
These companies have specialty products.
Lattice, better known for its CPLDs, have also an "instant-on" FPGA family.
Actel and QuickLogic have antifuse (programmable-only-once) products.
FPGAs vs. CPLDs
Are FPGAs and CPLDs the same thing? No. Both are programmable digital logic chips. Both are made by the same companies. But they have different characteristics.
FPGAs are "fine-grain" devices. That means that they contain a lot (up to 100000) of tiny blocks of logic with flip-flops. CPLDs are "coarse-grain" devices. They contain relatively few (a few 100's max) large blocks of logic with flip-flops.
FPGAs are RAM based. They need to be "downloaded" (configured) at each power-up. CPLDs are EEPROM based. They are active at power-up (i.e. as long as they've been programmed at least once...).
CPLDs have a faster input-to-output timings than FPGAs (because of their coarse-grain architecture, one block of logic can hold a big equation), so are better suited for microprocessor decoding logic for example than FPGAs.
FPGAs have special routing resources to implement efficiently binary counters and arithmetic functions (adders, comparators...). CPLDs do not.
FPGAs can contain very large digital designs, while CPLDs can contain small designs only.
What are FPGAs?
FPGAs are programmable digital logic chips. What that means is that you can program them to do almost any digital function.
Here's the general workflow when working with FPGAs:
You use a computer to describe the "logic function" that you want. You might draw a schematic, or create a text file describing the function, doesn't matter.
You compile the "logic function" on your computer, using a software provided by the FPGA vendor. That creates a binary file that can be downloaded into the FPGA.
You connect a cable from your computer to the FPGA, and download the binary file to the FPGA.
That's it! Your FPGA behaves according to your "logic function".
Keep in mind that
You can download FPGAs as many time as you want - no limit - with different functionalities every time if you want. If you make a mistake in your design, just fix your "logic function", re-compile and re-download it. No PCB, solder or component to change.
The designs can run much faster than if you were to design a board with discrete components, since everything runs within the FPGA, on its silicon die.
FPGAs loose their functionality when the power goes away (like RAM in a computer that looses its content). You have to re-download them when power goes back up to restore the functionality.
Who makes FPGAs?
There are (at least) 5 companies making FPGAs in the world. The first two (Xilinx and @ltera) hold the bulk of the market.
Xilinx is the biggest name in the FPGA world. It tends to be the density and technology leader.
@ltera is the second FPGA heavyweight, also a well-known name.
Lattice, Actel, Quicklogic are much smaller and are the "specialty shops".
Xilinx
Xilinx has traditionally been the silicon technology leader.
Biggest and most flexible (feature-full) devices.
Complex architecture.
Xilinx general philosophy is to provide all the features possible, at the cost of extra complexity. @ltera philosophy is different.
@ltera
Lean and efficient device architectures.
Easy to use devices, less features.
Lattice, Actel and Quicklogic
These companies have specialty products.
Lattice, better known for its CPLDs, have also an "instant-on" FPGA family.
Actel and QuickLogic have antifuse (programmable-only-once) products.
FPGAs vs. CPLDs
Are FPGAs and CPLDs the same thing? No. Both are programmable digital logic chips. Both are made by the same companies. But they have different characteristics.
FPGAs are "fine-grain" devices. That means that they contain a lot (up to 100000) of tiny blocks of logic with flip-flops. CPLDs are "coarse-grain" devices. They contain relatively few (a few 100's max) large blocks of logic with flip-flops.
FPGAs are RAM based. They need to be "downloaded" (configured) at each power-up. CPLDs are EEPROM based. They are active at power-up (i.e. as long as they've been programmed at least once...).
CPLDs have a faster input-to-output timings than FPGAs (because of their coarse-grain architecture, one block of logic can hold a big equation), so are better suited for microprocessor decoding logic for example than FPGAs.
FPGAs have special routing resources to implement efficiently binary counters and arithmetic functions (adders, comparators...). CPLDs do not.
FPGAs can contain very large digital designs, while CPLDs can contain small designs only.
FPGA:Field Programmable Grip Array
nothing but array of gates in achip ,which u can program according to your need ,u can program them using verilog and u can implement using fpga kit after synthesis.
Added after 13 seconds:
FPGA:Field Programmable Grid Array
nothing but array of gates in achip ,which u can program according to your need ,u can program them using verilog and u can implement using fpga kit after synthesis.
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