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Posts posted by anirbax

  1. Hi,

    Is it possible to access the SPI flash on the Papillio One board from my Verilog code?

    Some part of the  flash is taken by  the bitfile for loading FPGA configuration, and I'd

    like to use some free flash blocks (a few hundred bytes)

    My RTL receives data from a UART interface, processes it (SHA-1) and needs to store

    the signature on non-volatile storage. If not, I will  have to get a  separate SPI flash

    chip for storage.




  2. Hi,

    I am trying out the newbie example here:

    (plan to load design onto a Papilio One 250)


    Running synthesis gives this error:

    Starting Placer
    Phase 1.1
    ERROR:Place:311 - The IOB clk is locked to site IPAD21 in bank 0. This violates the SelectIO banking rules. Other
       incompatible IOBs may be locked to the same bank, or this IOB may be illegally locked to a Vref site.
    ERROR:Place:207 - Due to SelectIO banking constraints, the IOBs in your design cannot be automatically placed.

    The constraint file (downloaded from here)

         NET clk      LOC="P89"  | IOSTANDARD=LVCMOS25 | PERIOD=31.25ns;    

    When I change the IO type to IOSTANDARD=LVCMOS33, PnR completes without error.

    What could be the reason why 2.5V CMOS is not supported?