05-21-2017 11:40 AM
I am using the xilinx virtex5 xc5vlx110t with ML523 board.
I coded by using VHDL, and now it only need to synthesize to FPGA using planahead and iMPACT.
I tested simply using led, it was easily successful.
but the real test I'm going to do is see the bits that are output through the oscilloscope.
I dont know how to do pin mapping. I read the user guide but could not understand it. What is REF DES and what does
ML523 correspond to?
In the LED test, the number of LEDs on the board was assigned by Planahead.
But I do not know which pin to choose to see through the oscilloscope.
What I have done is assigning to the pin corresponding to the 20. GTP transceiver pins,
but the pin below the ML523 in this table could not be found on the board.
I guess the REF DES number is the same as the number on the board.
I do not know why LEDs are displayed in the ML523 table instead of REF DES.
And I have assigned it and uploaded the program through iMPACT,
but even if I connect the oscilloscope to the pin, the output does not come out and it keeps running.
What should I do?
05-21-2017 02:33 PM
@likeeternity I am assuming you have seen this document: https://www.xilinx.com/support/documentation/boards_and_kits/ug225.pdf
In that document REF DES is just a piece of text on the PCB which you can read. It's normally useless for FPGA design purposes. What you need for pin assignment is the ML523 column, say, on table 10. Here LED1 has REF DES DS23 and it's connected to FPGA pin AA26 on your board. AA26 is what you use for the pin assignment.
For easy probing you should be able to use the "SMA clock input" connectors described on table 8 & 9. Even though they're marked as inputs, this being an FPGA there is no reason you can't use them as output and it's easy to probe them with a scope. Just use AF19 pin as an output to drive a signal to start with.
05-21-2017 10:17 PM
thank you for your reply.
but I cannot solve my problem.
According to your reply I did the pin mapping "AF19" but it cannot output the signal.
when I test using led of table 10 ( pin number AA26) , led can operate on - off per 1 second.
and I changed AA26 to AF19 but it did not work.
I used clk "AG21" which is global clk, in ML523board, so I don't need to use external clk. I use only ml523 board and
oscilloscope for observation.
05-21-2017 11:16 PM
when you say "and I changed AA26 to AF19 but it did not work. " do you mean you probed the center conductor of the SMA marked with REF DES AF19 on the bottom left of your board while connecting the ground of your probe to the outside of the SMA connector and didn't see a 1 second pulse?