topic GPMI- Where does my recieved data end up? in i.MX Processors https://community.nxp.com/t5/i-MX-Processors/GPMI-Where-does-my-recieved-data-end-up/m-p/300056#M37642 <HTML><HEAD></HEAD><BODY><P>I'm working on an iMX6 GPMI interface to an asynchronous NAND flash.&nbsp; Taking baby steps, I have been able to issue a reset to the chip and now I'm trying to read it's id.&nbsp; The ID is 5 bytes long and when i set up the dma chain, I see that it actually respond with the right id, but the data is never moved to my buffer.&nbsp; I see the last byte in the GPMI_DATA register, and if i change my dma number of bytes to recieve to 4, i see the first 4 bytes so i know that the GPMI is recieving the data from the NAND.&nbsp; Also, the GPMI_STAT shows that the fifo is empty(bit2).&nbsp; So, where did my data go?</P><P>I set the GPMI_PAYLOAD to point to a static local variable, made sure it was word aligned, but nothing shows up there.&nbsp; I had some difficulties initially until i realized that the address registers all needed to be actual addresses, not the mapped address i am used to looking at, but once i changed all addresses by the offset that they are mapped to, my DMA command word chains work great.&nbsp; I'm puzzled because my DMA Read commands work fine, i used a similar local variable to store all my commands and just point the DMA buffer to them, with the offset.&nbsp; It appears that the DMA write isn't working.&nbsp; </P><P>Any suggestions, am i even looking at the right place?&nbsp; What could cause my DMA write to not write, but not report any errors?</P></BODY></HTML> Sat, 17 May 2014 03:05:00 GMT briannorman 2014-05-17T03:05:00Z GPMI- Where does my recieved data end up? https://community.nxp.com/t5/i-MX-Processors/GPMI-Where-does-my-recieved-data-end-up/m-p/300056#M37642 <HTML><HEAD></HEAD><BODY><P>I'm working on an iMX6 GPMI interface to an asynchronous NAND flash.&nbsp; Taking baby steps, I have been able to issue a reset to the chip and now I'm trying to read it's id.&nbsp; The ID is 5 bytes long and when i set up the dma chain, I see that it actually respond with the right id, but the data is never moved to my buffer.&nbsp; I see the last byte in the GPMI_DATA register, and if i change my dma number of bytes to recieve to 4, i see the first 4 bytes so i know that the GPMI is recieving the data from the NAND.&nbsp; Also, the GPMI_STAT shows that the fifo is empty(bit2).&nbsp; So, where did my data go?</P><P>I set the GPMI_PAYLOAD to point to a static local variable, made sure it was word aligned, but nothing shows up there.&nbsp; I had some difficulties initially until i realized that the address registers all needed to be actual addresses, not the mapped address i am used to looking at, but once i changed all addresses by the offset that they are mapped to, my DMA command word chains work great.&nbsp; I'm puzzled because my DMA Read commands work fine, i used a similar local variable to store all my commands and just point the DMA buffer to them, with the offset.&nbsp; It appears that the DMA write isn't working.&nbsp; </P><P>Any suggestions, am i even looking at the right place?&nbsp; What could cause my DMA write to not write, but not report any errors?</P></BODY></HTML> Sat, 17 May 2014 03:05:00 GMT https://community.nxp.com/t5/i-MX-Processors/GPMI-Where-does-my-recieved-data-end-up/m-p/300056#M37642 briannorman 2014-05-17T03:05:00Z