2 Replies Latest reply on Mar 8, 2011 2:54 AM by gautam.das.g

    PSoC5 ADC eoc signal question

    schurtz.li

      Hi:

         

      I try to use EOC signal of ADC as trigger, but it failed. Then I put the EOC on output pin, and capture by Oscilloscope. EOC is hi instead of a pulse.

         

      API ADC_1_IsEndConversion() polling indicates the convertion works well. EOC signal is hi, not toggled.

         

      Can you help? Attached my schematic in experiment

        • 1. Re: PSoC5 ADC eoc signal question
          schurtz.li

          Hi:

             

          I can describe it detailly. 

             

          Firstly, I try to use EOC rising edge to trigger an IRQ every time ADC convertion complete,  but only the first time ADC completion can trigger the IRQ. Then I connect the EOC to an output pin, and capture by Scope, I found the signal kept high instead of pulse.

             

          Thanks.

          • 2. Re: PSoC5 ADC eoc signal question
            gautam.das.g

            Hi Schurtz,

               

             

               

            This issue has been documented in the PSoC 5 errata.

               

            It is as follows:

               

            "PROBLEM DEFINITION
            End-of-conversion (EOC) is signaled by a status register bit, decimator interrupt, decimator DMA, and DSI
            routable signal. The DSI routable signal does not work. The CPU can poll the status register bit or use the
            decimator interrupt or decimator DMA.

               

            SCOPE OF IMPACT
            The ADC end-of-conversion (EOC) output of the PSoC Creator component can only be used to route to one
            DMA channel. The EOC output cannot be used to route through the DSI routing to any other digital resources.
            The decimator DMA route bypasses the DSI routing avoiding this issue. The decimator interrupt integrated
            into the PSoC Creator component also bypasses the DSI routing. All other possible EOC connections require
            DSI routing.

               

            WORKAROUND
            The CPU can poll the EOC bit in the status register or use the decimator interrupt to signal the digital system
            using firmware and a control register.

               


            FIX STATUS
            Silicon revision fix available in ES2.