LPC Microcontrollers中的主题 Re: Underclocking SDRAM https://community.nxp.com/t5/LPC-Microcontrollers/Underclocking-SDRAM/m-p/522275#M4911 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by mc on Wed Jul 15 09:45:19 MST 2015</STRONG><BR /><SPAN>Hi Mindebender,</SPAN><BR /><SPAN>SDRAM will work after programming it with correct timings viz CAS, refresh time etc.</SPAN></BODY></HTML> Wed, 15 Jun 2016 17:54:06 GMT lpcware 2016-06-15T17:54:06Z Underclocking SDRAM https://community.nxp.com/t5/LPC-Microcontrollers/Underclocking-SDRAM/m-p/522274#M4910 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by MindBender on Wed Jul 15 05:58:16 MST 2015</STRONG><BR /><SPAN>The Embedded Artists LPC1788 board uses an IS42S32800B-7BL SDRAM chip, which is 256Mbit (8Mx32) in size and specifies a clock rate of 143MHz. However, the demo software that comes with the board sets CCLKSEL to 0x00000101 and EMCCLKSEL to 0x00000001, operating this SDRAM chip at 60MHz.</SPAN><BR /><BR /><SPAN>Is it safe/reliable to underclock SDRAM (that far)? If so, do we need to alter latencies to make sure it is still refreshed in time?</SPAN><BR /><BR /><SPAN>We found the IS42S32800B-7BL a bit too big/expensive for our own design, so we have found an alternative, but that one too is rated well over 60MHz.</SPAN></BODY></HTML> Wed, 15 Jun 2016 17:54:06 GMT https://community.nxp.com/t5/LPC-Microcontrollers/Underclocking-SDRAM/m-p/522274#M4910 lpcware 2016-06-15T17:54:06Z Re: Underclocking SDRAM https://community.nxp.com/t5/LPC-Microcontrollers/Underclocking-SDRAM/m-p/522275#M4911 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by mc on Wed Jul 15 09:45:19 MST 2015</STRONG><BR /><SPAN>Hi Mindebender,</SPAN><BR /><SPAN>SDRAM will work after programming it with correct timings viz CAS, refresh time etc.</SPAN></BODY></HTML> Wed, 15 Jun 2016 17:54:06 GMT https://community.nxp.com/t5/LPC-Microcontrollers/Underclocking-SDRAM/m-p/522275#M4911 lpcware 2016-06-15T17:54:06Z