topic Re: Bidirectional SPI communication in i.MX Processors https://community.nxp.com/t5/i-MX-Processors/Bidirectional-SPI-communication/m-p/175941#M6609 <HTML><HEAD></HEAD><BODY><P>In order to use SSP for bidirectional data transfer, I think we have to use SSP without DMA. To do a single transmission should not be difficult but in order to handle it efficiently for multi words transmission using interrupt driven routines will be completely different.</P><P>I really like to see examples on accessing the SSP data FIFO directly too. There is very little information about it in the datasheet. I cannot even find out the size of the FIFO!</P></BODY></HTML> Mon, 23 Jul 2012 03:27:49 GMT Conrad1z 2012-07-23T03:27:49Z Bidirectional SPI communication https://community.nxp.com/t5/i-MX-Processors/Bidirectional-SPI-communication/m-p/175940#M6608 <HTML><HEAD></HEAD><BODY><P>The i.MX28 has a single DMA channel for SSP. So, only half-duplex transmission is possible in DMA mode. But "The SPI bus is inherently a full-duplex bidirectional interface" (17.5.1 in the reference manual).</P><P>How can I set up a single bidirectional transmission (Write data register -&gt; start transmission -&gt; read data register)? &nbsp;</P></BODY></HTML> Thu, 19 Jul 2012 07:12:45 GMT https://community.nxp.com/t5/i-MX-Processors/Bidirectional-SPI-communication/m-p/175940#M6608 AndresErni 2012-07-19T07:12:45Z Re: Bidirectional SPI communication https://community.nxp.com/t5/i-MX-Processors/Bidirectional-SPI-communication/m-p/175941#M6609 <HTML><HEAD></HEAD><BODY><P>In order to use SSP for bidirectional data transfer, I think we have to use SSP without DMA. To do a single transmission should not be difficult but in order to handle it efficiently for multi words transmission using interrupt driven routines will be completely different.</P><P>I really like to see examples on accessing the SSP data FIFO directly too. There is very little information about it in the datasheet. I cannot even find out the size of the FIFO!</P></BODY></HTML> Mon, 23 Jul 2012 03:27:49 GMT https://community.nxp.com/t5/i-MX-Processors/Bidirectional-SPI-communication/m-p/175941#M6609 Conrad1z 2012-07-23T03:27:49Z Re: Bidirectional SPI communication https://community.nxp.com/t5/i-MX-Processors/Bidirectional-SPI-communication/m-p/175942#M6610 <HTML><HEAD></HEAD><BODY><P>Did you make any progress on an i.MX28 full-duplex SPI driver?</P><P></P><P>Regards,</P><P></P><P>S</P></BODY></HTML> Wed, 21 Nov 2012 02:01:27 GMT https://community.nxp.com/t5/i-MX-Processors/Bidirectional-SPI-communication/m-p/175942#M6610 spearson 2012-11-21T02:01:27Z Re: Bidirectional SPI communication https://community.nxp.com/t5/i-MX-Processors/Bidirectional-SPI-communication/m-p/175943#M6611 <HTML><HEAD></HEAD><BODY><P>All,</P><P></P><P>Now, I am using L2.6.35_1.1.0-BSP.</P><P>I also have the same problem as you.</P><P></P><P>Is this problem solved in mainline kernel?</P><P></P><P>Best Regards,</P><P>George</P></BODY></HTML> Tue, 07 Jan 2014 14:03:20 GMT https://community.nxp.com/t5/i-MX-Processors/Bidirectional-SPI-communication/m-p/175943#M6611 george 2014-01-07T14:03:20Z