1 Reply Latest reply on Apr 9, 2016 9:41 AM by user_365962704

    Clearing Interrupt STATUS Register with DMA [SOLVED]

    user_365962704

      Hi all, hope everything goes well.

         

      I have been trying to get familiar with DMA and SPI Master, so i tried to join both topics in one project but i'm having troubles.

         

      Clearing the STATUS Register of the Tx Interrupt of the SPI by reading it inside an interrupt routine is easy, but it takes some CPU intervention (see picture isr_ClearTxSTATUSReg picture and isr file attached), so i was reading AN84810 and found an example where clearing the STATUS Register of PICU was done with DMA, it's just reading the Register to clear the interrupt flags, so i tried to read the SPI Tx Status Register via DMA, here's where i don't get what i expect, the TxInt signal seems not to get asserted when the bytes are sent (see DMA_ClearTxSTATUSReg picture and DMA project file attached).

         

       

         

      Any ideas on why i can not see the same TxInt signal behaviour on both cases? I was expecting a little pulse with the DMA approach, smaller than the pulse when i clear the register inside an interrupt.

         

      Hope i explain my problem, i'm not very good explaining xD

         

      Thanks in advance

         

      Carlos