Shanjit Singh

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Everything posted by Shanjit Singh

  1. Shanjit Singh

    Onboard Flash works how ?

    Hi I have used the Papilio and have implemented a few basic digital designs on it. I am planning to make a FPGA shield (XC3S250E) for an arduino footprint (based on an ARM Stellaris Cortex M3 processor). I have a doubt on how the onboard Flash of the Papilio is programmed. The FT2232 (USB-Serial/JTAG) is connected directly to the FPGA pins and unless there is some sort of a bootloader already burned onto the board, there shouldn't be anyway the SPI Flash gets initialized and stores any value. Am i correct on this ? How is the onboard flash implemented ? Thanks
  2. Shanjit Singh

    Onboard Flash works how ?

    I am attaching the board sch and brd files. I have divided my FPGA shield into two boards Top and Bottom, the top has the Break-out-board of the XC3s250E and some peripherals. The bottom does all the power supply and provides frequency to the top board and ofcourse attaches to the arduino footprint at the bottom. All this because i made all these PCBs (except the break-out-board) using the toner transfer method. I am attaching the sch and brd files of the top board and also a couple of images of the whole thing. http://db.tt/LHqQEv8U http://db.tt/gUiOOgcO http://db.tt/mmUkVWAW http://db.tt/BU8Rbic5
  3. Shanjit Singh

    Onboard Flash works how ?

    Okay, so as per my initial plan. I was able to make my own custom FPGA shield for an ARM Cortex M3 board (arduino footprint ofcourse!). I used the PapilioOne as reference for basic board design. There is no FT2232 on the board. I have been able to program the SRAM of the XC3S250E without any problem with my Digilent Adept Tool (JTAG-SPI Full Speed Cable). But unfortunately for me, my Serial Flash SPI based isn't working. I am using a M25P40 device which is supposed to be Xilinx Impact Compatible. Any Solutions ? I have been trying to generate a PROM file for the SPI using Impact and then create a SVF file using my generated bit file. But nothing happens. Any clues on what might i be doing wrong ? Thank you
  4. Shanjit Singh

    Onboard Flash works how ?

    I will look into this! Thanks! Actually the in-house method we folllow to make PCBs in our lab does not get the 48 LQFP pitch right and i would need to even send the prototype outside for manufacture. One more thing, can i take the FTDI into Optoisolator mode and then use the JTAG for programming the SPI flash on the papilio ? (say using the xc3sprog or papilio loader ?) Somehow this doesn't work for me..
  5. Shanjit Singh

    Onboard Flash works how ?

    Can there be one more way, Using the FT232 (has only the USB-Serial link unlike the FT2232, which has a USB-JTAG&Serial link). SO first i program the bscan_xc3s250e.bit file using the JTAG into the FPGA. Now the FPGA would have setup a proper RX-TX to SPI Flash interface on itself. I can then use the FT232 with the RX-TX pins to program the flash. Am i wrong anywhere conceptually ? I will have to practically try it out to confirm the working of everything. My propensity towards the FT232 being because of the package (easier to lab-manufacture and test) rather than the FT2232 (48 LQFP) not to mention the EEPROM.. Edit: I just had a look at http://forum.gadgetfactory.net/index.php?/topic/1224-programming-the-flash-using-jtag/ About the bscan and papilio "It uses the same method Impact does which is to load a special bitstream to the FPGA first. The bitstream uses the bscan primitive to make a connection from the jtag pins to the SPI flash. Then JTAG is used to load the data onto the SPI flash." So the bscan bitstream isn't actually connected the USB Rx/Tx to the SPI Flash but instead the JTAG interacts with the SPI Flash. So, what i said can't be done. I better change my SST based SPI Flash and use the Impact tool itself. Correct me if i am wrong. I am going through the source code at XC3sprog to be doubly sure..Thanks.
  6. Shanjit Singh

    Onboard Flash works how ?

    I hope i am able to! I follow you completely. Thank you Yep! I have a Digilent Adept (http://www.digilentinc.com/Products/Detail.cfm?Prod=ADEPT2) JTAG programmer and intend to use that. I also found out XC3sprog (http://sourceforge.net/projects/xc3sprog)and Digilent's Adept falls into their Cable list (fortunately!). I will try getting the SST Series Flash devices to work or else would jump onto a different supported Flash device.
  7. Shanjit Singh

    Onboard Flash works how ?

    Oh! But is it possible if i use something like http://www.xilinx.com/support/documentation/sw_manuals/xilinx11/pim_c_introduction_indirect_programming.htm with my XC3s250E (and SPI) and lose the FT2232 ? I shall be testing it out anyway. I only have a different flash than the ones pointed out in the above link..
  8. Shanjit Singh

    Onboard Flash works how ?

    I am grateful for such quick replies! I actually want to make my own board using only the JTAG connector (minus the USB and FT2232) and program both the SPI Flash and the FPGA, now since the SPI Flash is connected to the the FPGA directly how do i write my .bit file into the flash ? Papilio prog does all this using the bscan file in the background. Thanks for your link. I am working with the Papilio One. In my final design i would be removing the USB and FT2232. I found http://www.xilinx.com/support/documentation/sw_manuals/xilinx11/pim_c_introduction_indirect_programming.htm maybe this can sort things out. Just going through this..
  9. Shanjit Singh

    Onboard Flash works how ?

    Thanks i think i understand. The Papilio prog command papilio-prog.exe -v -f final.bit -b bscan_spi_xc3s250e.bit -sa -r will both initialize the SPI Flash and then burn the corresponding bit file onto the board as well. I tried this on my board and this works fine under linux also, which is pretty awesome! Thanks! Can i achieve the same thing by using the JTAG connectors directly ? As in suppose i use this http://www.digilentinc.com/Products/Detail.cfm?Prod=ADEPT2 , can i program the SPI flash using this ? I did try it out in the morning and i wasn't able to program the Flash but could program the XC3S250E directly. Anyway to program the flash ? Where can i find the bscan_spi_xc3s250e.bit source code ? I reckon i should take a look at it once.