revathi

Members
  • Content Count

    17
  • Joined

  • Last visited

About revathi

  • Rank
    Member

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. revathi

    xadc_zynq

    Hi @jpeyron , In my research work, my target is , the sampling frequency of digitizer should be 260 MHz. Now am using the xadc of Zynq 702. Do you have any idea of ADC that connects to zynq 702 board, that should have Maximum sampling frequency of 260MHz
  2. revathi

    xadc_zynq

    Hi eveyone, In UG480, XILINX manual, at page 25, "The ADCs always produce a 16-bit conversion result. The 12-bit data correspond to the 12 MSBs (most significant) in the 16-bit status registers. The unreferenced LSBs can be used to minimize quantization effects or improve resolution through averaging or filtering " UG480 Is it anyone give more details about the averaging used here. what is the actual averaging behind that four bits. Am not fully understand about the last 4 bits from XADC, am in need of more information regarding the bits. I have already posted the same question in XILINX too.
  3. revathi

    xadc_zynq

    Hi @jpeyron, I would like to do differentiation function on xadc output. Will you give some basic idea or any references for doing the differentiation function over the ADC output Thanking you
  4. revathi

    xadc_zynq

    Hi @jpeyron, In XADC wizard i make Vp and Vn as external ports. In XDC file i have given like below, set_property IOSTANDARD LVCMOS18 [get_ports vp_in_0] set_property IOSTANDARD LVCMOS18 [get_ports vn_in_0] set_property PACKAGE_PIN L11 [get_ports vp_in_0] set_property PACKAGE_PIN M12 [get_ports vn_in_0] * why there is a reduction in amplitude of xadc output when there is a increase in frequency. My understanding is that may be due to anti aliasing filter. If so, how to overcome that problem. Is it you have any idea regarding my issue. Thankyou for your support
  5. revathi

    xadc_zynq

    Hi @jpeyron, I have noticed one thing today, If I reduce the frequency , the ADC code gets increases like this. But its really look no meaning how it happens, why there is a indirect proportional to frequency and voltage. It may be due to any anti aliasing filter effects. I don,t know exactly. and still am not clear in Vn offset, I would like you to notice what I realized from the manual UG480. Kindly refer the figure below.
  6. revathi

    xadc_zynq

    Hi @jpeyron, I have attached my unipolar xadc output signal. Kindly check it off, the same deformation of voltage is there. Vp sinput signal is 0 to 1V, with offset of 500mV. Vn is from DAC B, default value is 0V. Freq from generator is 10Khz I don't understand why there is only 0.93V max and 0.3V minimum.
  7. revathi

    xadc_zynq

    Hi @jpeyron, The sampling rate is 961.54 Kbps I have attached my SDK code, for bipolar mode. Kindly go through it. Recently i got the waveform with proper shape and smoothing, the only thing is there is some deformation of voltage in output. Fig 3: TEST SIGNAL FOR BIPOLAR MODE _NO OFFSET FIG 4: INPUT SIGNAL (VP) CONNECTION FROM AWG TO FPGA KIT FIG 5 : TEST SIGNAL TO UNIPOLAR MODE 1. Weather configuring the bipolar / unipolar mode in XADC WIZARD is enough? 2. Or I need to make some changes in sdk code 3. My assumption is am doing some error in SDK code I will attach my SDK code , I followed the Adam taylor and this attached link for coding and referred the xsysmon .h lab 3 4. The boxed thing in sdk code was added myself for bipolar and unipolar 5. Is it necessary to give the coding which i have given inside the text box? 6. Is it am doing any error in code ? sdk code.docx
  8. revathi

    xadc_zynq

    Hi @jpeyron, I have tried today by applying the input from -500mV to +500mV, and i got the 16 bit ADC result. But i fully do not understand why i didnt get exactly the same input voltage range. some deformation in waveform is arising. (+0.436V and -0.392V am getting as output) At the same time the smoothing of output signal is not so fair. I have attached my ILA window and excel output. Kindly give a glance and thankyou for your continuous support. Horizontal Axis: No of samples Vertical axis: Output voltage value
  9. revathi

    xadc_zynq

    Hi everyone, I got the result for XADC , I applied a continuous sine wave signal to the dedicated pin Vp and Vn. I have debugged the value. I noticed the result is from 0000h to 7fffh only, but my input signal is from 0 to 1V , with 5000 mv Vn offset I have attached the ILA window also, what could be the reason for my output only from 0 to 0.5V
  10. revathi

    xadc_zynq

    Hi @jpeyron, Thankyou for your prompt reply. I have posted the same question in Xilinx forum. Thankyou
  11. revathi

    xadc_zynq

    Hi, I would like to give more detail about my work. If you look into he document AMS_101 , in page 34, Fig, 3.6. As of now, i have connected the Positive and negative terminal of input signal to J2 of Pin 1 and Pin2. In that particular figure, "Apply Negative Analog Input Voltage with “Vn Offset” Window in AMS Evaluator" * It is in the case of AMS GUI Evaluator. * I don't want to use AMS evaluator, so in my case how to apply Vn offset Thanking you
  12. revathi

    xadc_zynq

    Hi @jpeyron, Thankyou jpeyron for your kind reply. I have looked into the examples. Suddenly i had a small doubt. My question may be little basic. But, i need to clarify my confusion. As i mentioned in the previous post, i applied Vn offset as 500mV in arbitary waveform generator. 1) In AMS evauation card 101 here , i have connected the positive supply to Pin 1 of J2 and negative supply to pin 2 of J2 from arbitary waveform generator. 2) In Bipolar mode, i have given Vn offset in waveform generator. How i can set my Vn offset in XADC manually, is it possible to do so 3) Or setting Vn offset in waveform generator is enough
  13. revathi

    xadc_zynq

    Hi @jpeyron, Thankyou for your kind reply. As you said in page 22 of XADC user guide, the setting of bipolar selection is there. But am not instantiating the XADC using simulation code. I Exported my whole design to SDK and then i created an application project. In SDK, how to instantiated the bipolar selection. I attached my bipolar signal waveform and the C code i have used for my application. Kindly refer it. #include <stdio.h> #include "platform.h" #include "xadcps.h" #include "Xil_types.h" #include "sleep.h" #define XPAR_AXI_XADC_0_DEVICE_ID 0 //ID of xadc_wiz_0 #define XAdcPs_RawToExtVoltage(AdcData) ((((float)(AdcData))* (1.0f))/65536.0f) //(ADC 16bit result)/16/4096 = (ADC 16bit result)/65536 // voltage value = (ADC 16bit result)/65536 * 1Volt static XAdcPs XADCMonInst; //a XADC instance int main() { XAdcPs_Config *ConfigPtr; XAdcPs *XADCInstPtr = &XADCMonInst; //status of initialisation int Status_ADC; //Vp_Vn u32 VP_VNRaw; float VP_VNData; init_platform ( ); printf ("Zynq using vivado \n\r"); //XADC initialization ConfigPtr = XAdcPs_LookupConfig(XPAR_AXI_XADC_0_DEVICE_ID); if (ConfigPtr == NULL ) { return XST_FAILURE; } Status_ADC = XAdcPs_CfgInitialize(XADCInstPtr,ConfigPtr,ConfigPtr->BaseAddress); if ( XST_SUCCESS != Status_ADC ) { printf("XADC failed initial"); return XST_FAILURE; } // self test XADC Status_ADC = XAdcPs_SelfTest(XADCInstPtr); if (XST_SUCCESS != Status_ADC) { printf("XADC failed self test"); return XST_FAILURE; } XAdcPs_SetSequencerMode(XADCInstPtr,XADCPS_SEQ_MODE_SAFE); XAdcPs_SetSeqChEnables (XADCInstPtr, XADCPS_CH_AUX_MIN); "HERE HOW TO INSERT MY CODE FOR SELECTING BIPOLAR MODE" XAdcPs_SetSeqInputMode (XADCInstPtr, XADCPS_CH_AUX_MIN); XAdcPs_SetSequencerMode(XADCInstPtr,XADCPS_SEQ_MODE_CONTINPASS); while(1){ // VP_VN VP_VNRaw = XAdcPs_GetAdcData(&XADCMonInst,XADCPS_CH_AUX_MIN); VP_VNData = XAdcPs_RawToExtVoltage(VP_VNRaw); printf("Raw VP_VN %lu Data VP_VN %f \n\r", VP_VNRaw, VP_VNData); } return 0; } Thanking you,
  14. revathi

    xadc_zynq

    Hi @jpeyron, I have connected the board with aux 0 pin , and i got converted ADC output , but the values is in unipolar mode. From arbitary waveform generator, 1 Vpp external sine wave signal is given as input. But am getting the maximum of only around 70mv only, am not getting the full 500mv . And i have attached my ADC plotting result , kindly refer it. And how to set the bipolar mode in SDK, using c code. I referred some digilent forum answers but am not clear. Atlast, as XADC sampling rate is 1Ms/s but am getting around 300 samples/s, while am plotting my result in Serial oscilloscope (following lab3 )
  15. revathi

    xadc_zynq

    Hi @jpeyron, Thankyou for your kind reply. I will check the code that you have sent. The board that am using is Zynq ZC702, evalutaion kit. NO, I didn't try any auxillary channel. Today i will try and update you. Thankyou once again