Difference between FPGA and CPLD

[gbaerf]

Hi,

I tried but not finding any specific conclusion on it
what is the main difference between FPGA and CPLD
please give ur comment on this...

With Regards,

 

[kvingle]

try google .you will get a number of sites...

 

[hemanth]

CPLDs are buit with PROMS where as FPGAs will not contain PROM and theres architecture also differs

 

[dmk]

Try this:

The whole lot PLDs, SPLD, CPLDs and FPGAs are inside it.

 

[kvingle]

CPLDs are buit with PROMS where as FPGAs will not contain PROM and theres architecture also differs

their are various non-volatile variants available for FPGAs nowdays..(some are even with on chip NV memory)
such as spartan3A..and antifuse based FPGAs by actel....

 

[gbaerf]

Which is volatile and which is non-volatile ....

Added after 41 seconds:

I think FPGAs are volatile and CPLD are non-volatile ..

 

[kvingle]

Which is volatile and which is non-volatile ....

Added after 41 seconds:

I think FPGAs are volatile and CPLD are non-volatile ..

As i said before this definition is not right.Since today you can have
nonvolatile FPGAs also.e.g. Spartan3A (it is flash based)
and not only xilinx but almost every vendor today has a nonvolatile range of fpgas
available in their product lineup...

http://www.latticesemi.com/products/fpga/xp/index.cfm

**broken link removed**

http://www.actel.com/products/solutions/tsc/default.aspx

 

[gbaerf]

Hi kvingle,

thanks, u have cleared my doubts.....
so as per the present scenario we can make the difference only architecture wise.....we cannot have the clear differences because both does actually same job....

with regards,

 

[kvingle]

The one major difference that surely exist in between CPLD and FPGA is granularity.
The CPLDs are course and fpga are moderate or finely granular.

 

[vlsi_whiz]

CPLDs come from the PLD (Programmable Logic Devices) family. These are ROM based devices. Once programmed, the device will not loose its functionality even when it is powered down. CPLD architecture consists of programmable AND and OR matrix along with programmable interconnects. CPLDs also support multiple IO standards like LVTTL, LVCMOS, LVDS, PCI. CPLDs do not have built-in RAM or SRAM blocks. They have fixed delays and have better performance than FPGAs.

FPGAs on the other hand, are very flexible, SRAM based and volatile. They loose their configuration when powered down. Hence, FPGAs need PROM devices where the configuration data is stored on the PROM and the FPGA configures itself on power-up using this data.

FPGAs consists of SRAM blocks, programmable interconnects, CLB, LUTs. FPGA's are also called as LUT (Look-up Table) based. When an FPGA is configured, the bitstream is stored in the LUT or SRAM. FPGA's have programmable delays, ie, IO delays, CLB delays and PAD delays.

 

[kvingle]

CPLDs come from the PLD (Programmable Logic Devices) family. These are ROM based devices. Once programmed, the device will not loose its functionality even when it is powered down. CPLD architecture consists of programmable AND and OR matrix along with programmable interconnects. CPLDs also support multiple IO standards like LVTTL, LVCMOS, LVDS, PCI. CPLDs do not have built-in RAM or SRAM blocks. They have fixed delays and have better performance than FPGAs.

FPGAs on the other hand, are very flexible, SRAM based and volatile. They loose their configuration when powered down. Hence, FPGAs need PROM devices where the configuration data is stored on the PROM and the FPGA configures itself on power-up using this data.

vlsi_whiz........
FYI........

Which is volatile and which is non-volatile ....

Added after 41 seconds:

I think FPGAs are volatile and CPLD are non-volatile ..

As i said before this definition is not right.Since today you can have
nonvolatile FPGAs also.e.g. Spartan3A (it is flash based)
and not only xilinx but almost every vendor today has a nonvolatile range of fpgas
available in their product lineup...

http://www.latticesemi.com/products/fpga/xp/index.cfm

**broken link removed**

http://www.actel.com/products/solutions/tsc/default.aspx

and fpga is also a PLD...

 

[dmk]

As i wrote before, the only thing you should do is to have a glance on the book "Design Warrior Guide to FPGA (the link is in my previous post).

 

[rag.perfect]

I have posted one material regarding CPLD n FPGA at this link... plz check it out:

 

[vs21]

CPLD:

1. Made up of PROM's, so configuration is not volatile. That means, you can configure the device once and can reuse the same configuration. You can switch off the board and when you switch it on, you get the same programmed configuration on that CPLD device.
2. CPLD's are gate rich, that means they have fewer FF's and more number of gates. So, you had make sure in your logic design that, you use lesser FF's when you use CPLD's.
3. The cost of CPLD's are more compared to FPGA's

FPGA:

All the features are exactly to opposite the one mentioned above