topic how to use two dma in Kinetis Microcontrollers https://community.nxp.com/t5/Kinetis-Microcontrollers/how-to-use-two-dma/m-p/355965#M17767 <HTML><HEAD></HEAD><BODY><P>dear sir,</P><P>i am using K60 Tower board.i have uart communication both transmitting packets and receiving packets.</P><P>i coded for receving packet using dma with interrupt.I use channel 0 in dma0.receving packet comes in milli second </P><P>i have to transmit some bytes before i get receiving bytes.To ensure to get right packet bytes i use printf function.but the problem is that when i use printf function transmitting packet never goes.because may be crash with receiving packet.that i dont know when i remove printf working ok...but if the delay or some additional tasks that problem may be repeat.</P><P>how can i remove the problem</P><P>if i use dma for transmitting uart packets without interrupt,can i remove the problem</P><P>if i use two dma ,can use dma1 with channel 1?</P><P>actually i dont know when two dma with channel</P><P>tell me what i have to care when selecting two DMA....?</P><P>please</P></BODY></HTML> Fri, 27 Mar 2015 03:48:17 GMT lijofrancis 2015-03-27T03:48:17Z how to use two dma https://community.nxp.com/t5/Kinetis-Microcontrollers/how-to-use-two-dma/m-p/355965#M17767 <HTML><HEAD></HEAD><BODY><P>dear sir,</P><P>i am using K60 Tower board.i have uart communication both transmitting packets and receiving packets.</P><P>i coded for receving packet using dma with interrupt.I use channel 0 in dma0.receving packet comes in milli second </P><P>i have to transmit some bytes before i get receiving bytes.To ensure to get right packet bytes i use printf function.but the problem is that when i use printf function transmitting packet never goes.because may be crash with receiving packet.that i dont know when i remove printf working ok...but if the delay or some additional tasks that problem may be repeat.</P><P>how can i remove the problem</P><P>if i use dma for transmitting uart packets without interrupt,can i remove the problem</P><P>if i use two dma ,can use dma1 with channel 1?</P><P>actually i dont know when two dma with channel</P><P>tell me what i have to care when selecting two DMA....?</P><P>please</P></BODY></HTML> Fri, 27 Mar 2015 03:48:17 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/how-to-use-two-dma/m-p/355965#M17767 lijofrancis 2015-03-27T03:48:17Z Re: how to use two dma https://community.nxp.com/t5/Kinetis-Microcontrollers/how-to-use-two-dma/m-p/355966#M17768 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P></P><P>How are you transmitting the data, are you using polling or interrupt mode?</P><P></P><P>You need to ensure that the DMA requests are not enabled for transmission, this can cause a problem with the interaction between the core and the DMA engine. As I see the problem is that.The printf will work as a delay, because it takes a lot of time (I measured 10 ms at 21 MHz core frequency).</P><P></P><P>Please refer to this document and the example code for UART and DMA to check how the DMA is configured.</P><P></P><P><A href="https://community.nxp.com/docs/DOC-102981">Using the DMA module in Kinetis Devices</A></P><P><BR />Hope this information can help you</P><P></P><P>Best Regards,<BR />Adrian Sanchez Cano<BR />Technical Support Engineer<BR />-----------------------------------------------------------------------------------------------------------------------<BR />Note: If this post answers your question, please click the Correct Answer button. Thank you!<BR />-----------------------------------------------------------------------------------------------------------------------</P></BODY></HTML> Mon, 30 Mar 2015 17:06:35 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/how-to-use-two-dma/m-p/355966#M17768 adriancano 2015-03-30T17:06:35Z