Max V doubt

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MAXII/ V aren't typical CPLDs; their architecture is similar to FPGAs based on 4 input LUTs, register and a dense interconnect.

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thanks for the reaply. that helped me allot.

but made some questions too.

if MAX II/V have a similar FPGA architecture why they are still CPLDs?

if they have similar architecture, that means that the MAXs have unpredictable propagation times?

i believe that don't have Longer propagation times because they have Multitrack. am i wrong?

I've always understood one of the key differences between CPLDs and FPGAs to be that CPLDs are non-volatile. In other words CPLDs do not require an external configuration device (i.e. external non-volatile memory + controller) to configure them on power up.

Other sources (like wikipedia *wince*) may suggest other distinctions, but as technology advances these distinctions might get blurred.

This is the viewpoint I have found helpful when communicating with people in industry. If anyone more knowledgeable wants to instruct us with more precise definitions, please feel free.

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if MAX II/V have a similar FPGA architecture why they are still CPLDs?

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Altera designed them to replace their CPLD products and markets them as such.

But it's best if you think about them as a small simple FPGA with integrated flash to hold configuration (and other tidbits if you wish).

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if they have similar architecture, that means that the MAXs have unpredictable propagation times?

i believe that don't have Longer propagation times because they have Multitrack. am i wrong?

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Right on both counts.

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I've always understood one of the key differences between CPLDs and FPGAs to be that CPLDs are non-volatile. In other words CPLDs do not require an external configuration device (i.e. external non-volatile memory + controller) to configure them on power up.

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There are non-volatile FPGAs fom companies such as Actel and Lattice.

Xilinx also had a Spartan3 variant with integrated configuration memory.

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There are non-volatile FPGAs fom companies such as Actel and Lattice.

Xilinx also had a Spartan3 variant with integrated configuration memory.

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Thanks for the clarification. I guess the point I was trying to make is that often times I hear other engineers refer to non-volatile FPGAs as CPLDs simply because they don't require a configuration device. This generalization may be, at least in part, because of Altera's effort to cast the Max devices as CPLDs.