Difference between FPGA and CPLD

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senthilnathan.rajesh

Joined: 12 Apr 2006
Posts: 43

22 Feb 2007 6:40 Difference between FPGA and CPLD

Can anybody explain the main difference between a CPLD and a FPGA...? Whats the term used to mention the available Logic resources in CPLD and FPGA...?

Thanks

Sathish

Joined: 06 Jan 2006
Posts: 91
Helped: 4
Location: Chennai

22 Feb 2007 9:43 Re: Difference between FPGA and CPLD

COMPLEX PROGRAMABLE LOGIC DEVICE(CPLD) has less gate count as it is made of EPROM, flash technologies.

FIELD PROGRAMABLE GATE ARRAY(FPGA) are large gate count devices and is made of SRAM, antifuse technologies

Hence their architecture is also different.

you can get the difference between flash and antifuse technologies in internet.

zeeshanzia84

Joined: 29 May 2006
Posts: 202
Helped: 19
Location: Pakistan / Germany

22 Feb 2007 11:52 Re: Difference between FPGA and CPLD

No. Actually Satish is WRONG. FPGAs are available in fuse as well as antifuse type, and Flash as well as RAM and even EEPROM type.

Quote:

FIELD PROGRAMABLE GATE ARRAY(FPGA) are large gate count devices....COMPLEX PROGRAMABLE LOGIC DEVICE(CPLD) has less gate count

Actually, that is also not very correct. First of all "gate count" is only an advertising term....that allows you to VERY rough estimate where your programmable device stands in comparison to an ASIC based design flow....

Secondly, ofcourse you can get an FPGA with much lesser gate count as compared to a CPLD..
In reality, the difference lies in their architecture. The fundamental unit of almost all FPGAs is the LOGIC CELL which comprises of latches, a multiplexer and a LUT(which can act as 16 FFs or one 16x1 RAM)....this is a more complex architecture as compared to the CPLD whose LOGIC CELL has programmable arrays of ORs and ANDs....at the end of each logic cell of a cpld are certain FFs.....

Thus FPGAs are much versatile for Sequential logic based circuits...

Sathish

Joined: 06 Jan 2006
Posts: 91
Helped: 4
Location: Chennai

23 Feb 2007 6:48 Re: Difference between FPGA and CPLD

hi senthilnathan.rajesh

you can get the difference in there architecture and the application of FPGA and CPLD's in the following article.

http://www.netrino.com/Articles/ProgrammableLogic/index.php..

i accept you comment zeeshan..

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ankit12345

Joined: 27 Dec 2005
Posts: 292
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Location: bangalore,India

23 Feb 2007 7:06 Difference between FPGA and CPLD

FPGA and CPLD differ in architecture and technology

zeeshanzia84

Joined: 29 May 2006
Posts: 202
Helped: 19
Location: Pakistan / Germany

23 Feb 2007 20:55 Re: Difference between FPGA and CPLD

Quote:

i accept you comment zeeshan..

Thank you. That's very generous of you.

fahadislam2006

Joined: 09 Jan 2006
Posts: 51
Helped: 1
Location: Sweden

02 Mar 2007 15:10 Re: Difference between FPGA and CPLD

In simple you can say that before many years, when we were mot much mature in Digital Designing we designed simple Logical gates ... and then after time our needs grown and we turned to combining more and more Logical gates ... then to make connections clear, we arranged in form of arrays (PAL,PLA etc) and called then PLD and its more complex form as CPLD ...
after that some people felt that very soon our need will grow too much and we cannot create that much complex Arrays (CPLDs) so they turned to create some logical formation to arrange.
And decided to broke don system in little logical groups having its own centre (LUT), own memory and own interconnections. It also give advantage in terms of power as we can turn off unnecessary blocks.

And soon Human needs will grow and he will search some new way ... Very Happy