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Spartan-3 not configuring

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Advanced Member level 3
Oct 24, 2005
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i have designed a board, with spartan-3 FPGA.
I think the FPGA is not configuring after power-up.
the PROG_B is/goes high, but the INIT_B and the DONE are low.
there is no short circuit from these pins to GND or to neighbour pins.

at the first time, when turned on the board, the core VCC was 3.3V, because the soldering company made a mistake. we fixed it.
through the jtag, i can configure the platform flash, verification succeds.

Just because there is no short between pins does not mean that your part was not or is not damaged. The only way to know is to remove the suspect part and replace with a new or known good part. If you still experience the problem of not configuring then look at the circuit design to make sure it is correct then verify the PCB was laid out correctly.


i replqaced, but still...was.

then i made new bit file, new mcs memory file, so with that it was configuring already, DONE pin went high, FPGA started working.
i think the problem was a wrongly chosen flash size when making the mcs.


I am using spartan3 for my project to configure memory device. I needed 1.8V IO standard and found that spartan3 board may be configured for 1.8V output.

i have tried all the syntex be it either in verilog file (//synthesis ....) or in UCF file (NET "intense name" iostandard="---") but none seems to work.

I request to please tell me how to configure the IO standard for spartan 3 board.What and where is the command to be written....

Thanks in advance...

if you need 1,8V IO, you have to supply those IO banks with 1.8V on the board design. and set in the ucf as well.
(you will not to have 1.8V IO signals when supply is 3.3V. just think about how a CMOS output driver looks like)

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