topic SDHC with simple DMA? in Vybrid Processors https://community.nxp.com/t5/Vybrid-Processors/SDHC-with-simple-DMA/m-p/233218#M430 <HTML><HEAD></HEAD><BODY><P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; hi,I use the simple DMA mode of the SDHC' internal DMA with Vybrid Tower.The OS is MQX 4.0.2.When I select "DDR debug" with IAR,the file in the SD card was not written or readed correctly.But,when I select "Int Ram debug",the file was written or readed correctly.On the datasheet &lt;vybrid Reference manual&gt; page 2742,it say "the SDHC internal DMA does support&nbsp; a virtual memory system".I want to know ,how to use simple DMA in DDR mode with Vybrid Tower system?</P></BODY></HTML> Thu, 28 Nov 2013 01:40:35 GMT lizhenq 2013-11-28T01:40:35Z SDHC with simple DMA? https://community.nxp.com/t5/Vybrid-Processors/SDHC-with-simple-DMA/m-p/233218#M430 <HTML><HEAD></HEAD><BODY><P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; hi,I use the simple DMA mode of the SDHC' internal DMA with Vybrid Tower.The OS is MQX 4.0.2.When I select "DDR debug" with IAR,the file in the SD card was not written or readed correctly.But,when I select "Int Ram debug",the file was written or readed correctly.On the datasheet &lt;vybrid Reference manual&gt; page 2742,it say "the SDHC internal DMA does support&nbsp; a virtual memory system".I want to know ,how to use simple DMA in DDR mode with Vybrid Tower system?</P></BODY></HTML> Thu, 28 Nov 2013 01:40:35 GMT https://community.nxp.com/t5/Vybrid-Processors/SDHC-with-simple-DMA/m-p/233218#M430 lizhenq 2013-11-28T01:40:35Z Re: SDHC with simple DMA? https://community.nxp.com/t5/Vybrid-Processors/SDHC-with-simple-DMA/m-p/233219#M431 <HTML><HEAD></HEAD><BODY><P>&nbsp; I find the reason.The function&nbsp; fopen(ptr,flags)&nbsp; in MFS,.The "flags" is only suport "r" "r+" "w" "w+",so when use "rb+",it will not write data to file.</P></BODY></HTML> Thu, 28 Nov 2013 08:10:35 GMT https://community.nxp.com/t5/Vybrid-Processors/SDHC-with-simple-DMA/m-p/233219#M431 lizhenq 2013-11-28T08:10:35Z