fpga4fun.com

by **two_shoes_2002** » Sat Feb 21, 2004 11:37 pm

In the "What are FPGAs?" section it states:

"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. "

Is this true? The Altera FPGA I'm using right now doesn't need to be re-downloaded after losing power. I'm curious if others would need to be re-downloaded every time they power back up.

by **two_shoes_2002** » Sun Feb 22, 2004 12:01 am

Looking on the datasheet, it seems I have a CPLD... would this be the reason why it stays after power down?

by **fpga4fun** » Sun Feb 22, 2004 1:47 am

You probably have an Altera EEPROM on the board.
These can reconfigure the FPGA at each power-up.

There are plenty of other solutions to achieve that, like a CPLD and a flash memory, or a microcontroller.

by **two_shoes_2002** » Sun Feb 22, 2004 2:40 am

There isn't an eeprom on the board. It only has an octal buffer, a few resistor packs, and an Altera EPM7064SL44.

Now I'm really confused. :cry:

by **fpga4fun** » Sun Feb 22, 2004 2:48 am

The EMP7064 CPLD would need a memory to upload to the FPGA.
What FPGA are you using?

by **two_shoes_2002** » Sun Feb 22, 2004 3:44 am

The EMP7064 is what I'm using. So I guess it's not an fpga, right?

by **fpga4fun** » Sun Feb 22, 2004 3:55 am

no, that's a CPLD.

See this page (at the bottom)
http://www.fpga4fun.com/WhatAreFPGAs.html

by **two_shoes_2002** » Sun Feb 22, 2004 3:59 am

Yup... that's the page I was referring to in my original question. Thanks much!

fpga4fun.com

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FPGAs lose functionality?

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