Guest
#5140516
Here I am trying to make DAC work on boar of FPGA spartan 3E.I write code as per manual but it don't give desired output.I attached the code here. Can anyone tell me where the problem is?
Guest
#5140520
Look for a working SPI-Core and use it. Check the spi protocol with the datasheet of your SPI-DAC. Use simulation and compare the waveform of the simulator with that in your datasheet Does your spi-clk toggle? I guess not. And also check the direction of the port.
Guest
#5140614
Thank you for your response. my spi_sck is working proper. And I also check for SPI but I don't find any problem with it.I am beginner. if possible,can you explain in detail ?
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#5141343
Krishna wrote: > Thank you for your response. > my spi_sck is working proper. And I also check for SPI but I don't find > any problem with it.I am beginner. if possible,can you explain in detail > ? OK, I missed the toggling by "XOR 1'. See it seems to toggle. But i assume its not using a IOB-Flipflop. Have you set any constraint? Otherwise is likely that the sck takes some ns longer to propagate to the pin. Try post place&route simulation or use a scop and check spi set and hold times in respect to sck. https://forums.xilinx.com/t5/Embedded-Development-Tools/Post-Place-and-Route-simulation-with-MicroBlaze/td-p/356313
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#5141798
You are right it is about constrain, I try to solve it but not working. it is gives below warnings. can you tell me how to remove that warnings? WARNING:Xst:1293 - FF/Latch <dacsend_8> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_7> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_6> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_2> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_1> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_0> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_32> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_31> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_30> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_29> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_28> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_27> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_26> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_25> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_24> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_23> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_13> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_12> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_11> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_7> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_6> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_5> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_4> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_3> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_2> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_1> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_0> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_8> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_7> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_6> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_2> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_1> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacsend_0> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_32> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_31> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_30> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_29> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_28> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_27> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_26> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_25> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_24> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_23> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_13> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_12> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_11> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_7> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_6> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_5> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_4> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_3> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_2> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_1> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process. WARNING:Xst:1293 - FF/Latch <dacdata_0> has a constant value of 0 in block <DAC>. This FF/Latch will be trimmed during the optimization process.
Guest
#5155974
The warnings are just telling you that your signal "dacsend" is always set to all zeros. You never put any other value in there so you have a signal stuck at one value. This is usually not what you want and that is why you are getting a warning.
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