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Electronics => FPGA => Topic started by: Jane on December 18, 2015, 09:27:52 pm

Title: FPGA Xilinx XC3S400A
Post by: Jane on December 18, 2015, 09:27:52 pm
I have the same, two devices that use XC3S400A (FPGA made by Xilinx). One device  is working, the other not because the XC3S400A seems to be faulty.
I can not find already programmed XC3S400A.
Is it possible to read out the code from that working XC3S400A, then write the code to a brand new XC3S400A ?
How can I do that? What programmer do I need?
Thank you for your help
Title: Re: FPGA Xilinx XC3S400A
Post by: ElektroQuark on December 18, 2015, 09:31:00 pm
Common FPGAs are not programmed. They load the firmware from a flash or similar at boot time. So if the IC is really bad, change it.
Title: Re: FPGA Xilinx XC3S400A
Post by: asgard20032 on December 18, 2015, 09:46:05 pm
Or the pcb/other componnent around it are faulty.
Title: Re: FPGA Xilinx XC3S400A
Post by: marshallh on December 19, 2015, 12:52:49 am
Very unlikely that the fpga failed.

More likely is a PCB failure, passive copmnent failure or something else.
Title: Re: FPGA Xilinx XC3S400A
Post by: Jane on December 19, 2015, 07:09:35 am
Thank you for your replies.
FPGA is very hot and the device says, it could not initialize FPGA, so I would expect FPGA problem.

In general, can be FPGA replaced by a new one or each FPGA has security number so it cannot be simply replaced ?

Title: Re: FPGA Xilinx XC3S400A
Post by: Scrts on December 21, 2015, 09:47:44 pm
Very unlikely that the fpga failed.

More likely is a PCB failure, passive copmnent failure or something else.

Agreed.

Thank you for your replies.
FPGA is very hot and the device says, it could not initialize FPGA, so I would expect FPGA problem.

In general, can be FPGA replaced by a new one or each FPGA has security number so it cannot be simply replaced ?

Did you check power supplies? FPGAs don't die this way. Something caused this issue. Did you check all other possibilities? IO shorts, PCB damage, power supplies, etc?
Title: Re: FPGA Xilinx XC3S400A
Post by: Someone on December 22, 2015, 12:09:56 am
Thank you for your replies.
FPGA is very hot and the device says, it could not initialize FPGA, so I would expect FPGA problem.

In general, can be FPGA replaced by a new one or each FPGA has security number so it cannot be simply replaced ?
Did you check power supplies? FPGAs don't die this way. Something caused this issue. Did you check all other possibilities? IO shorts, PCB damage, power supplies, etc?
Thats exactly how FPGAs fail from over voltage or static damage, of course the power rails may be the underlying problem but the FPGA die will happily turn into a melted blob of a resistive heater.
Title: Re: FPGA Xilinx XC3S400A
Post by: mikeselectricstuff on December 22, 2015, 12:21:36 am
You should be able to just replace it, as its code comes from elsewhere in the system.
However This device does contain a unique serial number (Xilinx call it DigitalDNA), so if the manufacturer was extremely paranoid about copying they may have made use of it, however I'd say this was rather unlikely.