LPC Microcontrollers中的主题 Strange DMA Behaviour.Can someone help ???? https://community.nxp.com/t5/LPC-Microcontrollers/Strange-DMA-Behaviour-Can-someone-help/m-p/517755#M2331 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by leonardo on Sat Jun 30 13:56:21 MST 2012</STRONG><BR /><SPAN>Hi to forum </SPAN><BR /><SPAN>I wish to transfer some data from an spi memory (at26df081) to the internal ram&nbsp; of an LPC1754.I wish to use DMA in 16 bit mode which i found is the most efficient in terms of speed . I made the programming for the DMA controller and it works ok .After my first tests i show byte swapping since the writing is made in 8 bit mode.So i decided to use BIG endian mode transfer . Switching to big endian mode DMA fills the memory with zeros instead of my data . Has anybody noticed such a problem ?.Switching to little endian mode i see the data are correct but i must swap bytes .</SPAN><BR /><SPAN>Any ideas ?????.</SPAN><BR /><BR /><BR /><SPAN>&nbsp;&nbsp;&nbsp; </SPAN><BR /><BR /><BR /></BODY></HTML> Wed, 15 Jun 2016 17:33:02 GMT lpcware 2016-06-15T17:33:02Z Strange DMA Behaviour.Can someone help ???? https://community.nxp.com/t5/LPC-Microcontrollers/Strange-DMA-Behaviour-Can-someone-help/m-p/517755#M2331 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by leonardo on Sat Jun 30 13:56:21 MST 2012</STRONG><BR /><SPAN>Hi to forum </SPAN><BR /><SPAN>I wish to transfer some data from an spi memory (at26df081) to the internal ram&nbsp; of an LPC1754.I wish to use DMA in 16 bit mode which i found is the most efficient in terms of speed . I made the programming for the DMA controller and it works ok .After my first tests i show byte swapping since the writing is made in 8 bit mode.So i decided to use BIG endian mode transfer . Switching to big endian mode DMA fills the memory with zeros instead of my data . Has anybody noticed such a problem ?.Switching to little endian mode i see the data are correct but i must swap bytes .</SPAN><BR /><SPAN>Any ideas ?????.</SPAN><BR /><BR /><BR /><SPAN>&nbsp;&nbsp;&nbsp; </SPAN><BR /><BR /><BR /></BODY></HTML> Wed, 15 Jun 2016 17:33:02 GMT https://community.nxp.com/t5/LPC-Microcontrollers/Strange-DMA-Behaviour-Can-someone-help/m-p/517755#M2331 lpcware 2016-06-15T17:33:02Z Re: Strange DMA Behaviour.Can someone help ???? https://community.nxp.com/t5/LPC-Microcontrollers/Strange-DMA-Behaviour-Can-someone-help/m-p/517756#M2332 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by jdurand on Sat Jun 30 19:10:44 MST 2012</STRONG><BR /><SPAN>I haven't tried it, but since this is a 32 bit part, could you be swapping the upper 16 bits down to the lower 16 bits?</SPAN></BODY></HTML> Wed, 15 Jun 2016 17:33:03 GMT https://community.nxp.com/t5/LPC-Microcontrollers/Strange-DMA-Behaviour-Can-someone-help/m-p/517756#M2332 lpcware 2016-06-15T17:33:03Z