Real GPIF timing diagram not as timing at the GPIF II Desinger

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EvEv_2610591
Level 2
Level 2

I have a simple code to read data from FPGA using GPIF II and send via USB. I need only one RD signal to read data from FPGA bus. RD LOW level drive 16 bits data bus. RD HIGH close FPGA data bus and incremet internal FPGA adress counter. Each time I want to read data with different length.

DMA CONFIG code

/*------DMA P-Port config (AUTO mode)---------------------------------------------------------------------------------------------*/

dmaCfg.notification = 0;

dmaCfg.cb = NULL;

dmaCfg.prodSckId = CY_FX_PRODUCER_USB_SOCKET_4;

dmaCfg.consSckId = CY_FX_CONSUMER_PPORT_SOCKET;

dmaCfg.count = 1;

apiRetStatus = CyU3PDmaChannelCreate (&glChHandleSRamUtoP_48, CY_U3P_DMA_TYPE_AUTO, &dmaCfg);

if (apiRetStatus != CY_U3P_SUCCESS)

{

   CyU3PDebugPrint (CY_FX_DEBUG_PRIORITY, "CyU3PDmaChannelCreate failed, Error code = %d\n", apiRetStatus);

   CyFxAppErrorHandler(apiRetStatus);

}

dmaCfg.notification = 0;

dmaCfg.cb = NULL;

dmaCfg.prodSckId = CY_FX_PRODUCER_PPORT_SOCKET;

dmaCfg.consSckId = CY_FX_CONSUMER_USB_SOCKET_8;

dmaCfg.count = 1;

apiRetStatus = CyU3PDmaChannelCreate (&glChHandleSRamPtoU_48, CY_U3P_DMA_TYPE_AUTO, &dmaCfg);

if (apiRetStatus != CY_U3P_SUCCESS)

{

   CyU3PDebugPrint (CY_FX_DEBUG_PRIORITY, "CyU3PDmaChannelconfig Failed, Error code = %d\n", apiRetStatus);

   CyFxAppErrorHandler(apiRetStatus);

}

//------------------------------------------------------------------------------------------------------------------------------------------------------------------

Working cycle

for (;;)

    {

         uint32_t counter = 8;

         GpifReadEnd = CyFalse;

         CyU3PGpifInitAddrCounter (0, counter, CyFalse, CyTrue, 1);               // loading addr count

        

          apiRetStatus = CyU3PGpifSMSwitch (256, RD_START, 256, 0, 0);     // start condition after switch GPIF II

          if(apiRetStatus != CY_U3P_SUCCESS){

        

          CyU3PDebugPrint (CY_FX_DEBUG_PRIORITY, "CyU3PGpifSMSwitch failed, Error code = %d\r\n", apiRetStatus); }

          while(!GpifReadEnd){}              // FLAG that assert in interrupt function

          GpifReadEnd = CyFalse;

     }

        Why RD level is LOW after last read cycle on oscilloscope but in GPIF Desinger show RD = HIGH?

     When I tried to paste empty state between RD_START state and RD_LOW state, RD signal asserted HIGH, but I have one more read strobe. Why?????????

osc.jpg

diag.jpgdiag1.jpg

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2 Replies
Anonymous
Not applicable

Hi,

1) Please check if the signal polarity is set as active high and you de-assert the signal in read_low and assert the signal in read_high

or

2) Please check if the signal polarity is set as active low and you assert the signal in read_low and de-assert the signal in read_high

Please attach your whole state machine project (cydsn folder) for further review.

Regards,

-Madhu Sudhan

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My project files!

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