<moogyd@yahoo.co.uk> wrote in message
news:1187112403.482357.230890@d55g2000hsg.googlegroups.com...
>
> We are using a spartan evaluation board with some 7 segment LED's.
>
> If I make minor changes to the pinout, sometimes the FPGA stops
> functioning completely. What is interesting, is that the 7 segment
> LED's are not driven.
>
>
> Steven
>
Hi Steven,
Your VHDL is missing an 'end if' I think, and you should use numeric.std,
it's much nicer.
Have you 'loc'ked all the pins in your design? Does your design meet the
timing?
HTH., Syms.
Reply by ●August 14, 20072007-08-14
Hi,
I wonder if anyone has seen something like this.
I have an FPGA design targeted at an Spartan xc3s1500 and using
ISE8.2.
We are using a spartan evaluation board with some 7 segment LED's.
If I make minor changes to the pinout, sometimes the FPGA stops
functioning completely. What is interesting, is that the 7 segment
LED's are not driven. The VHDL code for this is :
p_seven_seg : process(clk system_reset_n,)
begin
if(system_reset_n = '0')then
seven_seg_1 <= "1111111";
elsif(clk = '1'and clkt'event) then
case (conv_integer(p1)) is
when 0 =>
seven_seg_1 <= not("0111111");
when others =>
seven_seg_1 <= "1111111";
end case;
end process;
There are no tri-state buffers, seven_seg_1 is an O/P port therefore
should *always* be driven.
This failure mode implies (to me) that FPGA configuration is failing.
Has anyone seen anything like this, can they suggest any debug
strategies?
Thanks,
Steven