Kinetis MicrocontrollersのトピックSimultaneous DMA transfer for DAC and I2C FRDMK64F https://community.nxp.com/t5/Kinetis-Microcontrollers/Simultaneous-DMA-transfer-for-DAC-and-I2C-FRDMK64F/m-p/728220#M44538 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P>&nbsp; I am transferring PCM audio to DAC peripheral via DMA in circular manner. Here the DMA is continuous and triggered by PIT at 44100 Hz. I cannot halt this at any time. I am decoding MP3 and transferring to DAC via DMA, while DMA is throwing first half of PCM, I will be decoding and filling second half and vice versa, this is working fine for now.</P><P></P><P></P><P>&nbsp;I am transferring a frame buffer to OLED in one shot which I tested already with DMA transfer and it is working fine. But if DAC transfer is already happening via DMA as a continuous circular process and in the middle of it how can I do I2C transfer via DMA without affecting the DAC transfer ?</P><P></P><P>Currently I couldn't find a solution so I am using I2C BULK transfer via Interrupt in non blocking mode which works fine for me with a little penalty of ISR hit which is ok for my application. But I am curious to know if there is any way to do both DMA simultaneously ?</P><P></P><P>It seems like it is having only one DMA0 in hardware and I don't know if it can do simultaneous transfer.</P><P></P><P>Any clue?</P></BODY></HTML> Tue, 16 Jan 2018 09:11:02 GMT vinods 2018-01-16T09:11:02Z Simultaneous DMA transfer for DAC and I2C FRDMK64F https://community.nxp.com/t5/Kinetis-Microcontrollers/Simultaneous-DMA-transfer-for-DAC-and-I2C-FRDMK64F/m-p/728220#M44538 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P>&nbsp; I am transferring PCM audio to DAC peripheral via DMA in circular manner. Here the DMA is continuous and triggered by PIT at 44100 Hz. I cannot halt this at any time. I am decoding MP3 and transferring to DAC via DMA, while DMA is throwing first half of PCM, I will be decoding and filling second half and vice versa, this is working fine for now.</P><P></P><P></P><P>&nbsp;I am transferring a frame buffer to OLED in one shot which I tested already with DMA transfer and it is working fine. But if DAC transfer is already happening via DMA as a continuous circular process and in the middle of it how can I do I2C transfer via DMA without affecting the DAC transfer ?</P><P></P><P>Currently I couldn't find a solution so I am using I2C BULK transfer via Interrupt in non blocking mode which works fine for me with a little penalty of ISR hit which is ok for my application. But I am curious to know if there is any way to do both DMA simultaneously ?</P><P></P><P>It seems like it is having only one DMA0 in hardware and I don't know if it can do simultaneous transfer.</P><P></P><P>Any clue?</P></BODY></HTML> Tue, 16 Jan 2018 09:11:02 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/Simultaneous-DMA-transfer-for-DAC-and-I2C-FRDMK64F/m-p/728220#M44538 vinods 2018-01-16T09:11:02Z Re: Simultaneous DMA transfer for DAC and I2C FRDMK64F https://community.nxp.com/t5/Kinetis-Microcontrollers/Simultaneous-DMA-transfer-for-DAC-and-I2C-FRDMK64F/m-p/728221#M44539 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P></P><P>The K64 has one eDMA module, which could allow one channel be active at the same time.</P><P>Customer can try to use the channel preemption mechanism.</P><P>I2C related DMA channel with higher priority.</P><P>Customer could try and check if the transfer data to DAC be affected during I2C DMA channel active phase.</P><P>Thank you for the attention.</P><P><BR />Have a great day,<BR />Mike</P><P></P><P>-----------------------------------------------------------------------------------------------------------------------<BR />Note: If this post answers your question, please click the Correct Answer button. Thank you!<BR />-----------------------------------------------------------------------------------------------------------------------</P></BODY></HTML> Thu, 18 Jan 2018 04:19:41 GMT https://community.nxp.com/t5/Kinetis-Microcontrollers/Simultaneous-DMA-transfer-for-DAC-and-I2C-FRDMK64F/m-p/728221#M44539 Hui_Ma 2018-01-18T04:19:41Z