topic Re: How to find the correct timming values for the SDRAM controller in LPC Microcontrollers https://community.nxp.com/t5/LPC-Microcontrollers/How-to-find-the-correct-timming-values-for-the-SDRAM-controller/m-p/562388#M16481 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by bavarian on Thu Oct 04 04:44:19 MST 2012</STRONG><BR /><SPAN>Hello Lars,</SPAN><BR /><BR /><SPAN>Of course a lot of things depend on the type of SDRAM connected to the LPC4350.</SPAN><BR /><SPAN>The Excel file is attached. It contains calculation for a different SDRAM (32-bit SDRAM).</SPAN><BR /><SPAN>I think the comment "// calculated from xls sheet" was left in the code but the value changed.</SPAN><BR /><BR /><SPAN>However, we are currently reviewing all these drivers for various platforms, if we identify problems we will try to fix them.</SPAN><BR /><BR /><SPAN>There is init code attached which works for the Hitex board, but I wouldn't call it reference code. I know that it works on 96MHz EMC frequency, for 102 MHZ I need to do some tests.</SPAN><BR /><BR /><SPAN>Regards,</SPAN><BR /><SPAN>NXP Technical Support Team</SPAN></BODY></HTML> Wed, 15 Jun 2016 18:44:30 GMT lpcware 2016-06-15T18:44:30Z How to find the correct timming values for the SDRAM controller https://community.nxp.com/t5/LPC-Microcontrollers/How-to-find-the-correct-timming-values-for-the-SDRAM-controller/m-p/562387#M16480 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by larsjep on Wed Oct 03 08:09:59 MST 2012</STRONG><BR /><SPAN>Hi,</SPAN><BR /><BR /><SPAN>I having some trouble understanding how the timming values are calculated.</SPAN><BR /><BR /><SPAN>If I look in lpc43xx_emc.c (from the PDL) line 198, there is a comment saying: "// calculated from xls sheet"</SPAN><BR /><BR /><SPAN>Is this xls sheet available somewhere ?</SPAN><BR /><BR /><SPAN>Ex. if I look at the value for DYNAMICRP it is set to 1. (in lpc43xx_emc.c line 198)</SPAN><BR /><SPAN>This should give a tRP of 2xCLK = 19.6ns (When running at 102Mhz)</SPAN><BR /><SPAN>But the datasheet for the SDRAM on the Hitex board states minimum 20ns (-7 speed)</SPAN><BR /><BR /><SPAN>Shouldn't the DYNAMICRP be set to 2 then ?</SPAN><BR /><SPAN>Or should the EMC_CLK_DELAY also be involved in the calculation ?</SPAN><BR /><BR /><SPAN>Also the DYNAMICRAS seems incorrect. This is set to 3 =&gt; 39.2ns, but the datasheet for the RAM states minimum 42ns</SPAN><BR /><BR /><SPAN>Best regards</SPAN><BR /><SPAN>&nbsp; Lars </SPAN></BODY></HTML> Wed, 15 Jun 2016 18:44:29 GMT https://community.nxp.com/t5/LPC-Microcontrollers/How-to-find-the-correct-timming-values-for-the-SDRAM-controller/m-p/562387#M16480 lpcware 2016-06-15T18:44:29Z Re: How to find the correct timming values for the SDRAM controller https://community.nxp.com/t5/LPC-Microcontrollers/How-to-find-the-correct-timming-values-for-the-SDRAM-controller/m-p/562388#M16481 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by bavarian on Thu Oct 04 04:44:19 MST 2012</STRONG><BR /><SPAN>Hello Lars,</SPAN><BR /><BR /><SPAN>Of course a lot of things depend on the type of SDRAM connected to the LPC4350.</SPAN><BR /><SPAN>The Excel file is attached. It contains calculation for a different SDRAM (32-bit SDRAM).</SPAN><BR /><SPAN>I think the comment "// calculated from xls sheet" was left in the code but the value changed.</SPAN><BR /><BR /><SPAN>However, we are currently reviewing all these drivers for various platforms, if we identify problems we will try to fix them.</SPAN><BR /><BR /><SPAN>There is init code attached which works for the Hitex board, but I wouldn't call it reference code. I know that it works on 96MHz EMC frequency, for 102 MHZ I need to do some tests.</SPAN><BR /><BR /><SPAN>Regards,</SPAN><BR /><SPAN>NXP Technical Support Team</SPAN></BODY></HTML> Wed, 15 Jun 2016 18:44:30 GMT https://community.nxp.com/t5/LPC-Microcontrollers/How-to-find-the-correct-timming-values-for-the-SDRAM-controller/m-p/562388#M16481 lpcware 2016-06-15T18:44:30Z Re: How to find the correct timming values for the SDRAM controller https://community.nxp.com/t5/LPC-Microcontrollers/How-to-find-the-correct-timming-values-for-the-SDRAM-controller/m-p/562389#M16482 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by VijayM on Thu Dec 13 01:14:37 MST 2012</STRONG><BR /><SPAN>In excel sheet from whered does tSUd in front of CAS1, CAS2, CAS3 is picked? </SPAN><BR /><SPAN>What is this tSUd?</SPAN></BODY></HTML> Wed, 15 Jun 2016 18:44:30 GMT https://community.nxp.com/t5/LPC-Microcontrollers/How-to-find-the-correct-timming-values-for-the-SDRAM-controller/m-p/562389#M16482 lpcware 2016-06-15T18:44:30Z