Hi All, Non-ROACH user here … but a Xilinx tool user.
The default for unused pins in ISE is to enable pull-downs on unused pins. If your SPI pins do not have a pin constraint, then they may just be getting pulled low. If the SPI select is active low (likely), then the chip is being selected. If your pin constraints file does not have the SPI signals defined, then use the BitGen option to use pull-ups on unused pins. The Tcl command is: project set "Unused IOB Pins" "Pull Up" -process "Generate Programming File" Alternatively, you can add pins to your constraints file, and use the “S” option to stop ISE deleting them during synthesis. You can then turn on pull-ups/downs on a per pin basis, eg., here’s some lines from my Avnet Spartan-6 Microboard constraints file … # PHY interface NET "eth_resetN" LOC = T18 | IOSTANDARD = LVCMOS33 | S | TIG; NET "eth_col" LOC = M18 | IOSTANDARD = LVCMOS33 | S | PULLDOWN; NET "eth_crs" LOC = N17 | IOSTANDARD = LVCMOS33 | S | PULLDOWN; NET "eth_rx_clk" LOC = L15 | IOSTANDARD = LVCMOS33 | S; NET "eth_rx_d<0>" LOC = T17 | IOSTANDARD = LVCMOS33 | S | PULLUP; NET "eth_rx_d<1>" LOC = N16 | IOSTANDARD = LVCMOS33 | S | PULLUP; NET "eth_rx_d<2>" LOC = N15 | IOSTANDARD = LVCMOS33 | S | PULLUP; NET "eth_rx_d<3>" LOC = P18 | IOSTANDARD = LVCMOS33 | S | PULLUP; Given that the ROACH flow is mostly automated, this last option might be the simplest. Just add the SPI constraints. Cheers, Dave From: Jack Hickish [mailto:jackhick...@gmail.com] Sent: Thursday, February 22, 2018 9:25 AM To: casper@lists.berkeley.edu Subject: Re: [casper] dac mkid spi problem Hi Paolo, OK, let me know! Jack On Thu, 22 Feb 2018 at 08:14 Paolo Fresch <paolo.fres...@gmail.com<mailto:paolo.fres...@gmail.com>> wrote: Thank you Jack, so far the method we have found to fix this issue works as long as we keep the roach up, thus the undriven-SPI do not bother us that much. I had a look at the verilog hdl, I am quite use to verilog and SPI (I did something similar for an I2C interface) but I can't say the same for OPB bus, power-pc's and so on... it will take me a while I guess. I will contact you when I will be on it. Cheers, Paolo 2018-02-20 19:57 GMT+01:00 Jack Hickish <jackhick...@gmail.com<mailto:jackhick...@gmail.com>>: Hi Paolo, If I'm reading the code correctly -- https://github.com/casper-astro/mlib_devel/blob/roach2/xps_library/%40xps_adc_mkid/xps_adc_mkid.m -- I believe that none of the SPI pins are driven. I have no idea whether any of these pins are pulled in any particular direction on the hardware since I haven't checked the schematics. I don't think there is a ready-to-use PPC<->SPI block, but there should be a variety of examples of SPI interfaces for other ADCs in the library -- https://github.com/casper-astro/mlib_devel/blob/roach2/xps_base/XPS_ROACH_base/pcores/opb_adc5g_controller_v1_00_a/hdl/verilog/opb_adc5g_controller.v Integrating such an interface shouldn't be that hard, though involves getting dirty with the toolflow. If you're sure this is your problem and want a hand, give me a shout and I'll try and find the time to help you do this. Cheers Jack On Mon, 19 Feb 2018 at 09:36 Paolo Fresch <paolo.fres...@gmail.com<mailto:paolo.fres...@gmail.com>> wrote: Dear all, I am a technical research fellow at INFN sezione di Roma, I am experiencing strange issue using roach + mkid DAC/ADC board<https://static1.squarespace.com/static/59c075f56f4ca3a44435bdb9/t/59f4e9ae24a694055a5761ad/1509222838779/MKID_DAC_ADC_brief.pdf> . Basically, after a “cold” startup the DAC does not generate the correct sinusoid but either nothing or something senseless. I have a bit of hardware background especially in serial chip-to-chip buses, I think it is a problem due to the SPI DAC configuration bus that should be tied to Virtex-6. In fact, if I “touch” the SPI connector on the DAC/ADC board the DAC starts to output the correct signal. Since no pcore is connected to these pin (and matlab prompt a warning while compiling using casper_xps toolchain) I think this strange behavior is caused by the undriven pin (at least the spi_resetn) on Virtex side. Can you confirm that these pins are undriven in the last update of the yellow block present in the casper mlib_devel ? There is any block in the casper xps_base or xps_library I can use to interface the PPC with the SPI? Do I need to design this block from scratch? Can you help me on this? Thank you in advance. BR, Paolo Fresch -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu<mailto:casper@lists.berkeley.edu>" group. To unsubscribe from this group and stop receiving emails from it, send an email to casper+unsubscr...@lists.berkeley.edu<mailto:casper+unsubscr...@lists.berkeley.edu>. To post to this group, send email to casper@lists.berkeley.edu<mailto:casper@lists.berkeley.edu>. -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu<mailto:casper@lists.berkeley.edu>" group. To unsubscribe from this group and stop receiving emails from it, send an email to casper+unsubscr...@lists.berkeley.edu<mailto:casper+unsubscr...@lists.berkeley.edu>. To post to this group, send email to casper@lists.berkeley.edu<mailto:casper@lists.berkeley.edu>. -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu<mailto:casper@lists.berkeley.edu>" group. To unsubscribe from this group and stop receiving emails from it, send an email to casper+unsubscr...@lists.berkeley.edu<mailto:casper+unsubscr...@lists.berkeley.edu>. To post to this group, send email to casper@lists.berkeley.edu<mailto:casper@lists.berkeley.edu>. -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu<mailto:casper@lists.berkeley.edu>" group. To unsubscribe from this group and stop receiving emails from it, send an email to casper+unsubscr...@lists.berkeley.edu<mailto:casper+unsubscr...@lists.berkeley.edu>. To post to this group, send email to casper@lists.berkeley.edu<mailto:casper@lists.berkeley.edu>. -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu" group. To unsubscribe from this group and stop receiving emails from it, send an email to casper+unsubscr...@lists.berkeley.edu. To post to this group, send email to casper@lists.berkeley.edu.
